		***  MIGHTY PHYSICS  REVIEW NOTES ***


INERTIA-- The property of matter that opposes any change in its 
		state of motion.

MASS-- the quantity of matter measured by its inertia.

MASS DENSITY-- mass per unit volume.  D = M/V

ENERGY-- the capacity to do work.

POTENTIAL ENERGY-- stored energy.

KINETIC ENERGY-- energy in motion.

RELATIONSHIP BETWEEN MATTER AND ENERGY--  E = mc2  where m 
			is mass and c is the speed of light (300,000 Km/sec).

ACCURACY-- compares well with accepted values.

PRECISION-- gives consistent results. (An instrument could be 
		    precisely inaccurate).

SIGNIFICANT DIGITS-- those digits in a number that are known with 
				    certainty plus the first digit that is uncertain.

ROUNDING OFF-- your answer must be rounded off to the least 
			    number of significant digits in the given data.

ORDERS OF MAGNITUDE-- powers of ten, each order of magnitude is 
					a ten fold change in the value of a number.

INTERPOLATION-- using a graph to find values between the known 
			     points.

EXTRAPOLATION-- using a graph to find values beyond the last  
			     point.

VECTOR-- a line with an arrow head whose length represents 
		magnitude and whose direction is indicated by the arrow.

SPEED-- a change in position with respect to time.  v = d/t

VELOCITY-- a speed in a given direction.  It's a vector quantity.

RESULTANT-- the vector which forms the diagonal of the 
		      parallelogram drawn with two vectors as sides. 
		      It can be solved graphically or by trigonometry.

EQUILIBRANT-- the vector which is equal and opposite to the 
			 resultant.

ACCELERATION -- a change in velocity with respect to time. a = v/t. 
			    It contains two units of time, v = d/t and a = v/t, 
			    so its unit may be meters per second per second 
			    (or m/s2).


ACCELERATION EQUATIONS are to be found in the text. 
			   Copy them and learn them!

FREELY FALLING BODIES--  objects dropping with no friction (as in a 
			   vacuum).

ACCELERATION DUE TO GRAVITY--    g = 9.8 m/s2  for all freely 
			   falling bodies at sea level.

TERMINAL VELOCITY--  considering friction, wind friction increases 
			   with velocity until the force of friction equals an 
			    object's weight. For people it is about 170 km/hr.  
			    For a leaf it's a few cm/s.  Cats survive great falls.

EQUATIONS FOR FREELY FALLING BODIES-- are the same as those for 
			    accelerated objects with "a" replaced with "g".

NEWTON'S LAWS OF MOTION:

     1. The Law of INERTIA states that an object will either remain at 
			  rest or continue to move at constant velocity in a 
			  straight line unless acted upon by an external force.

     2. The Law of ACCELERATION states that the acceleration of a 
			 body is directly proportional to the applied force 
			 and inversely proportional to its mass.

				  a = f/m    or    f = ma

     3. The Law of INTERACTION states that for every action there is 
			an equal and opposite reaction.

					  mV = Mv

	       where m is mass of smaller body, V is velocity of smaller 
	       body, and M is mass of larger body, v is velocity of the  
	       larger body.

THE UNIT OF FORCE is the "newton", "n".  One n of force will 
		   accelerate a one kilogram mass at the rate of one 
		   meter/second/second.

			       f = ma,    so   1n = (1Kg)(1m/s/s)

WEIGHT is the force of gravity,

	   since   f = ma,  then   wt = mg

     so a beefer whose mass is 80kg, will weigh 784n  (wt = 
	   (80kg)(9.8m/s/s).


NEWTON'S LAW OF GRAVITATION:

	  Every body attracts every other body with a force which is 
	  directly proportional to the product of their masses and  
	  inversely proportional to the square of the distance between 
	  their centers.

				    F = GMm/d2

	  where F is the force of attraction in n, M is the mass of the 
	  large object, m is the mass of the small object, d is the 
	  distance between their centers, and G is the gravitational 
	  constant (a constant to make the units work out).

	  For example, you on the Earth.  F is your weight, M is the 
	  mass of the earth, m is your mass, and d is the distance to the 
	  center of the earth (6300 Km = 6.3 X 106 meters). 
	  (G = 6.67 X 10-11 nm2/kg2).


RESOLUTION OF FORCES-- starting with the resultant, we find two 
components of it. The resultant is the diagonal of the parallelogram 
drawn with the two forces as sides. For example, a car on a slope has 
a gravity vector (its weight) acting straight toward the center of the 
earth. We will resolve this single force into the force acting to push 
the car down the slope and the force pressing the car into the 
roadway (the squish down force).

FRICTION-- a force that resists motion. For rough surfaces, it caused 
primarily by interlocking edges.  For smooth surfaces, molecular 
attraction becomes important.

     The coefficient of friction is the ratio of the force of friction 
(needed to keep the object moving) to the normal force (the vector 
component at right angles to the surface.

EQUILIBRIUM-- a state in which all force vectors are balanced.  There 
will be no change in the motion of the object.

PARALLEL FORCES-- forces acting in the same or opposite directions 
at different points on an object.

CENTER OF MASS-- the point where all the mass appears to be 
concentrated. A spun object will spin around its center of mass. The 
Earth and Moon revolve about their common center of mass (which 
is located about 1000 Km inside the Earth).  Double stars revolve 
about their common center of masses.

CENTER OF GRAVITY-- the point where the object's weight appears 
to be concentrated.  It is the balance point. The center of mass and 
the center of gravity are at the same point.

TORQUE is force times its distance from the center of rotation.

EQUILIBRIUM is composed of two parts:

     TRANSLATIONAL equilibrium-- from place to place. There will be 
no change in velocity along a line. The resultant is balanced by the 
equilibrant.

     ROTATIONAL equilibrium-- no change in rotational velocity.  The 
clockwise torque's are balanced by the counterclockwise torque's.

SOLVING EQUILIBRIUM PROBLEMS:

     TRANSLATIONAL-- the sum of the parallel forces in one direction 
must equal the sum of the parallel forces in the other direction (the 
ups = the downs).

     ROTATIONAL-- the sum of the clockwise torque's must equal the 
sum of the counterclockwise torque's.

TRAJECTORY is the path taken by a thrown body.  It is the result of 
the forward velocity and gravity.  It forms a parabola.

CENTRIPETAL FORCE is the center seeking force, say gravity for a 
satellite or the tension on a string for an object spun around by a 
cord.

CENTRIFUGAL FORCE is the center fleeing force caused by the 
object's inertia trying to keep it going in a straight line.

		      F = mv2/r

	  where  f = centrifugal force, m is mass of object and r is the 
	  radius of curvature.


IN ORBIT the centrifugal acceleration is equal to the centripetal 
acceleration.
						  _____
	  Critical velocity for an orbit,   v = \/ rg where r is radius of 
curvature and g is acceleration of gravity (9.8 m/s2).

ROTARY MOTION is measure in revolutions/s, or radians/s. A radian 
is 57.3 degrees.

FORMULAS FOR ANGULAR VELOCITY are to be found in the text. 
Copy them and be familiar with them.

GYROSCOPES exhibit two forms of weird action:

   Gyroscopic inertia which resists change at right angles to the 
force.

   Gyroscopic precession which is circular motion caused by an 
unbalanced force on the gyroscope.  The Earth precesses once every 
26,000 years due to the unbalanced force of the Moon.

HARMONIC MOTION is motion that repeats in a regular pattern. 
Examples are pendula and bobbing masses on springs.

THE PENDULUM is a mass suspended such that it can swing to and 
from.

     The period is the time for one complete swing (one cycle).
     Frequency is the number of swings per second.

THE LAWS OF THE PENDULUM.

     The period is independent of mass.
     The period is independent of displacement.
     The period is directly proportional to the square root of the 
	    length.
     The period is inversely proportional to the square root of 
	    gravity.


	  The formula         T = 2pi [sq rt of (l/g)]

		      where T is the period, l is the length, and g is the 
acceleration of gravity (9.8 m/s/s)

WORK is force times distance,  W = fd , the force is in newtons, the 
distance is in meters, and the work is (n)(m) which is called Joules.
     One joule of work is done when a force of one newton acts 
through a distance of one meter.

     No matter how big the force is, if you don't move something, you 
do no work. (Physics only pays for that which is accomplished).

     When moving an object up an incline, the work is in two parts, 
that used to overcome friction plus that used to overcome gravity.  
The gravity vector acts straight down and therefore the distance 
that the force of gravity moves is the height the object is lifted and 
not the length of the incline.

SIMPLE MACHINES:

     The lever and its three classes--

	  First class has the fulcrum between the load and the force. 
	       An example is the crow bar or see-saw.
	  Second class has the load between the force and the fulcrum. 
	       An example of this is the wheel barrow.
	  Third Class has the force between the load and the fulcrum. 
	      This gives a speed advantage as in the catapult, baseball 
	       bat, or shovel.

     The Wheel and Axle
     The Pulley
     The Inclined plane
     The Screw
     The Wedge

THEORETICAL MECHANICAL ADVANTAGE is determined by the ratio 
of distances.

	  TMA = dist moved by force/dist moved by load

ACTUAL MECHANICAL ADVANTAGE is determined by the ratio of 
load to force.

	  AMA = load/force

EFFICIENCY is the ratio of AMA/TMA expressed in percent. A 
machine is never 100% efficient because of frictional losses of work.

INPUT is the work put into a machine, that is the force X the dist. it 
moves

		 Input = fD

OUTPUT is the work delivered by the machine, that is the force X its 
distance

		 Output = Fd

EFFICIENCY can also be expressed by the ratio of output/input in 
percent.

POWER is the rate of doing work.  That is work divided by time.

    P = W/t   where P is the power in watts, W is the work in joules, 
and t is the time in seconds.

POTENTIAL ENERGY is energy that is stored, as in a raised blade of la 
Guillotine. Potential energy is weight X height.  Remember that 
weight is in newtons and is found by Newton's Second Law, f = ma, 
where m is in Kg and a will be for gravity. That is wt = mg.  So

		PE = mgh

KINETIC ENERGY is energy in motion.  Like that of a speeding steam 
locomotive.

	       KE = 1/2 mv2

LAW OF CONSERVATION OF MECHANICAL ENERGY-- the sum of the 
potential and
kinetic energy in a system is constant.  That is

	       KE = PE   so mgh = 1/2 mv2

MOMENTUM is the product of mass times velocity.

	       p = mv

IMPULSE is the product of force times time and is equal to the 
change in momentum

	       Ft = m/\v

CONSERVATION OF MOMENTUM-- the total momentum of a system 
remains constant.

COLLISION ACTION (crash)--

     Inelastic collisions (bump-stick):
	  The momentum of the crasher + the momentum of the 
crashee = 0

	       Mv + mV = 0

     Elastic collisions (bump-bounce):
	  The vector sums of momentum are equal (see a text for gory 
details).

ANGULAR MOMENTUM is also conserved as in the ice skater spin.

PROPERTIES OF MATTER:

ELEMENT is a form of matter that cannot be simplified by chemical 
means.  A basic substance.

COMPOUND is a substance composed of two or more elements 
chemically combined.

ATOM is the smallest particle of an element.

MOLECULE is the smallest particle of a compound.

PROTON is a basic particle whose mass is 1 g/mol, and whose charge 
is +1.

ELECTRON is a basic particle whose mass is 1/1837 g/mol and 
whose charge is -1.

NEUTRON is a basic particle whose mass is 1 g/mol and whose 
charge is 0.

ATOMIC NUMBER, the whole number on the Periodic Chart, is the 
number of protons in the nucleus, and also the number of electrons 
around the nucleus (provided that the atom is not ionized).

MASS NUMBER is the sum of protons and neutrons in a nucleus 
(because each of these particles has a mass of 1 g/mol).  This is not 
found on the Periodic Chart.

ISOTOPE is a different mass for the same element caused by a 
different number of neutrons in the nucleus.

ATOMIC WEIGHT, the decimal numbers on the Periodic Chart, is the 
average of the mass numbers of the isotopes of an element.

PHASES OF MATTER:

     SOLID-- the molecules are packed tightly together vibrating in 
position in their regular crystalline array. It has a definite shape and 
volume.

     LIQUID-- the molecules are close but loose and are able to tumble 
over one another.  It has a definite volume but assumes the shape or 
its container.

     GAS-- the molecules are relatively far apart (average distance at 
room temperature is 300 diameters). It has no definite shape and it 
expands to fill its container.

THE KINETIC THEORY: Atoms and molecules are in motion.  The 
warmer they are the faster they move.

     EVIDENCES SUPPORTING THE KINETIC THEORY--

	  Expansion upon heating.  Hot molecules move faster and 
bump their neighbors harder therefore pushing them further apart.  
(Note that the molecules themselves do not expand).
	  Gas pressure.  Molecular collisions impart force.
	  Vapor pressure.  Molecules escaping a liquid exert force (an 
example is steam power).
	  Diffusion of molecules is the intermingling of particles due to 
molecular motion. It's faster at higher temperatures.
	  Osmosis is diffusion through a porous membrane. Heavier 
molecules diffuse more slowly as a function of the square root of 
their molecular masses (Graham's Law).
	  Brownian Motion is the vibrations of microscopic particles as 
they are struck by moving molecules.  It's faster at higher 
temperatures.


VAN DER WAALS FORCES are the weak attractions between 
molecules caused by the electrons of one molecule attracting the 
protons of another molecule.  These are what causes molecular 
solids to form. Molecular solids are non-crystalline, like butter or 
wax.

CRYSTALLINE SOLIDS are formed by ionic or covalent bonding 
wherein electrons are transferred or shared. (The molecular solid, 
with its van der waals forces, is not considered to be bonded).

PROPERTIES OF SOLIDS:

     Adhesion is the attraction of unlike molecules like water and 
skin.
     Cohesion is the attraction of like molecules like mercury.
     Tensile strength is the force per unit area needed to break a 
substance measured in n/m2.
     Ductility is the ability for a solid to be drawn into wire.
     Malleability is the ability of a metal to be hammered or rolled 
into sheets.
     The metallic bond is caused by free electrons roaming through 
the atoms without being associated with particular atoms 
(delocalized).  Because of this, metals are flexible, ductile, and 
malleable.
     Elasticity is the ability of a solid to return to its original shape or 
size after having been distorted. If the solid is stressed too far, it will 
have reached its Elastic Limit.
     Stress is the ratio of force to area,  stress = F/A.
     Strain is the ratio of the change of length to the original length.
     Hooke's Law states that strain is directly proportional to stress.
     Young's Modulus, the numerical value of Hooke's Law, is the ratio 
of stress to strain.  Y = stress/strain.

LIQUIDS:

     In a liquid the molecules are close together but loose so that they 
are free to tumble over one another.

     Viscosity is the resistance to flow.  A viscous liquid flows slowly 
(i.e.. molasses).

     Volatility means easily vaporized.  Alcohol and water are volatile.

     Surface tension is a film-like layer on a liquid due to the inward 
attraction of the molecules (cohesion) not being balanced by an 
outward attraction.  This causes droplets to form spheres, and 
allows small objects to stand on the surface (like water skeeters, 
razor blades and the like).

     The meniscus is the curved surface of a liquid in a container due 
to surface tension.  For water it curves upward at the edges.

     Capillarity is the rising or depressing of liquid levels in tubes of 
small diameter. It is the result of the adhesion of the liquid to the 
tube and the surface tension.  Mercury is depressed in a tube with a 
positive meniscus because its cohesion for itself is stronger than its 
adhesion for the glass tube. Liquids rise if they wet the tube.

     Expansion on freezing of water occurs because water molecules 
form a ring structure with a hole in the center.  This causes water to 
expand by ten percent as it freezes.  This expansion exerts enormous 
force (80,000 n/cm2) which breaks rocks as the first step in the 
production of soil.

     Ice floats because of this expansion which gives it a density of 0.9 
g/cm3 vs 1 g/cm3 for liquid water. Hence ice bergs float with 90% 
of the ice below water level.

     Regelation is the melting of a ice by pressure and its re-freezing 
when the pressure is released. Examples are glacier movements and 
ice skating wherein the pressure of the blades melts the ice and the 
melt water refreezes immediately.

     Vapor pressure is the force per unit area exerted by evaporating 
molecules escaping through the surface tension.  An example is a 
boiler explosion.

     Boiling Point is the temperature at which the vapor pressure 
equals the atmospheric pressure.

     Boiling can be accomplished by two methods:

	  1. Raise the vapor pressure to atmospheric by heating 
(molecules move faster and have higher energy to break the surface 
tension).
	  2. Lower the atmospheric pressure to the vapor pressure (by a 
pump     or by condensing steam in a closed flask).

     Pressure is the force per unit area.

     Pascal's Principle states that the pressure in a confined fluid is 
transmitted undiminished in all directions. This is the principle of 
hydraulics wherein enormous forces can be produced by 
transmitting the pressure over very large areas. P = F/A, so F = PA.

     Archimedes Principle states that an immersed body is buoyed up 
by a force equal to the weight of the displaced fluid.  This is the 
principle that describes why ships float in water and lighter-than-air 
craft will rise.

     Bernoulli's Principle states that for fluids in motion, the faster 
the forward velocity, the less pressure is exerted sideways. (The 
molecules are striking objects at the side with glancing blows).  This 
is the principle of airplane lift, curving baseballs, bulging 
convertible tops, the carburetor, and the Brass Aspirator.

     Torricelli's Principle is that air has weight and therefore exerts 
pressure. Atmospheric pressure is measured with Torricelli's 
invention, the Barometer. The density of air is 1 gram per liter.

     Vacuum is the absence of matter (low pressure).  Air is removed, 
vacuums are not added. Suction is the process of the atmosphere 
PUSHING, vacuums cannot pull.

     Atmospheric Pressure, sea level average:
	  One Atmosphere.
	  Ten meters of water. (The average height that water can be 
pushed up at sea level by the atmosphere.
	  760 millimeters of mercury on the barometer.
	  One kilogram of mass per square centimeter (9.8 n of force).

THE HEAT IS ON:

     Thermal energy is the total potential and kinetic energy involved 
with molecular motion.

     Temperature is a function of the average rate of molecular 
motion.

     Heat is thermal energy that is absorbed, given up, or transferred 
form one body to another.

     The Celsius scale defines 0 as the temp of melting ice and 100 as 
the boiling point of water at one atmosphere of pressure (760mm on 
barometer).

     Common temperature:  Melting ice = 0 C, Room Temp = 20 C, 
Body temp = 37 C, Boiling water (at 1 atm) = 100 C, Red Hot = 800 
C.

     The Kelvin scale (absolute scale) is the Celsius scale starting at 
absolute zero which is -273 C.  K = C + 273.

     Absolute zero is the lowest temperature.  The molecules have 
minimum energy and very little motion.

     There is no such thing as "cold".  Cold means less heat.

     The calorie is the quantity of heat which will warm 1 g of water 1 
deg C.

     Specific Heat is the number of calories which will warm 1 g of 
substance by 1 deg C.  Most substances take less heat than water.
	  For water it is l cal/gC0, (the definition of the calorie).

     The formula is  Q = mc/\t  where Q is calories, m is mass in 
grams, and /\t is the temperature change in deg C.

     Thermal Expansion is caused by molecules bombarding each 
other and pushing each other farther apart. The molecules 
themselves do not expand.

     Charles's Law states that the volume of a gas varies directly as 
the absolute (Kelvin) temperature. Higher temp gives higher 
volume.

     Boyle's Law states that the volume of a gas varies inversely as the 
pressure.  Higher press gives smaller volume.  (The Squeeze is ON).

     FORMULAS:

	  PV = k  where  P  is pressure, V is volume, k is the gas constant

	  PV/T = P'V'/T'  where P,V,T are first press, vol, temp,

		and P',V',T' are the new press, vol, and temp.

	  PV = nRT  where  n is the number of moles of gas, and R is the 
"universal gas constant" (8.21 X 10-2 liter Atmos/mol K)

	  NOTE: The temperatures must be in K (absolute units).  K = C 
+ 273.

     STANDARD TEMPERATURE and PRESSURE, STP is 273 K, (0 C), 
and  1 atmos (760mm of Hg) pressure.

     Law of Heat Exchange states that  Heat lost = Heat gained, Ql = 
Qg.

     CHANGE OF PHASE require energy to rearrange molecules.

	  Heat of fusion (melting) breaks the crystalline bonds in the 
solid to form a liquid.
		    For water it is 80 cal/g

	  Heat of vaporization (to evaporate) separates the loose 
molecules in a liquid to form a gas in which the molecules are very 
far apart (av dist at room temp and press is 300 diameters).
	       For water it is 538 cal/g.

     HEAT PROBLEMS-- See the text p 190.

     Critical Temperature is the maximum temp above which a gas 
cannot be liquefied (no matter how high the pressure).

     Critical Pressure is the minimum press below which a gas cannot 
be liquefied (no matter how low the temp).


     HEAT AND WORK:

	  The First Law of Thermodynamics is the Law of Conservation 
of Energy.  Energy cannot be created nor destroyed, but only 
changed in form.

	  The Second Law of Thermodynamics is the Law of Entropy.  It 
states that energy tends to run down hill (hot to cold) and that 
matter tends to become less organized.  That is ENTROPY is the 
tendency to acquire MINIMUM ENERGY AND MAXIMUM 
RANDOMNESS.

	  Adiabatic temperature changes are those caused by expansion 
or contraction of gases.  Gases are heated adiabatically by 
compression as in Charles' Law. An example is in the diesel engine 
which ignites the fuel by the temperature of the adiabatic 
compression of air. Another example is in the formation of upslope 
fog in which the air is cooled by adiabatic expansion as it is blown 
uphill.


WAVES ACTION:

     WAVE-- a disturbance that propagates through a medium or 
space. It is in simple harmonic motion.

     TRANSVERSE WAVES vibrate at right angles to the direction of 
propagation.  They are composed of two parts, CRESTS and 
TROUGHS.

     LONGITUDINAL WAVES vibrate along the direction of travel.  
They are composed of COMPRESSIONS and RAREFACTIONS.

     CHARACTERISTICS of WAVES:

	  Wave length is the distance from one part to where that part 
repeats.  For example from crest to crest or compression to 
compression.

	  One Cycle is a complete vibration, ie. crest through trough.  
Its distance is the wave length.

	  The Frequency is the number of cycles per second, called Hz 
(hertz after Heinrich Hertz, discoverer of radio waves).

			 F = cycles/sec

	  The Period is the time for one cycle to pass a point.

			 T = 1/F

	  The Amplitude is the maximum displacement of a wave, i.e. 
		the height of a crest.

	  Amplitude Modulation (as in AM radio) is controlling the 
	       magnitude of the wave.

	  Frequency Modulation (as in FM radio) is controlling the rate 
of vibration of a wave.

	  The Power transmitted by a wave is proportional to both the 
amplitude and to the frequency squared. So if we double both the 
amplitude and the frequency of a wave, its power increases sixteen 
times!

	  The Wave Equation relating velocity, frequency and 
wavelength is

			   v = fl    l is usually the Greek letter, Lambda.


     PROPERTIES OF WAVES:

	  Rectilinear Propagation-- the wave front travels in straight 
lines from the point of origin.

	  Reflection is the bouncing of a wave off a barrier.  The Law of 
Reflection states that the angle of incidence is equal to the angle of 
reflection, i = r.

	  Impedance is the resistance to motion of a wave.

	       Impedance = wave-producing force/resulting velocity

	  Refraction is the bending of a wave as it passes from one 
medium into another.  It is caused by a change in velocity.

	  Diffraction is the spreading out of a wave as it passes a 
barrier.

	  Superposition of waves is the resultant vector addition of two 
or more waves passing through the same medium together.

	  Interference is the result of superposition.

	       Constructive interference is the adding of two waves to 
give a  stronger wave. This occurs when the crest of one meets the 
crest of another (or a compression meet a compression).

	       Destructive interference is the cancellation of waves when 
the crest from one meets the trough from another (or a compression 
meets a rarefaction.

	       Standing waves are the result of the interference of two 
waves of the same amplitude and wavelength traveling in opposite 
directions.

	       Nodes are the dead spots in standing waves. There is no 
vibration in a node.

	       Antinodes (or loops) are the positions of maximum 
vibration in a standing wave.

SOUND:

     Sound in physics is defined as compression/rarefaction waves in 
matter.

     Audible range for people varies between 20 Hz to 20,000 Hz.

     Infrasonic range are vibrations whose frequency is below the 
audible.

     Ultrasonic range are vibrations whose frequency is above the 
audible.

     Production of sound is accomplished by setting up vibrations in 
matter.  This can be done by vibrating solids, liquids, or gases.

     Sound waves are longitudinal (light waves are transverse).

     Sound needs a medium to carry it.  It doesn't travel through a 
vacuum.

     The speed of sound depends upon the medium and the 
temperature.  In air it travels at 331 m/s at 0 C and its speed 
increases by 0.6 m/s for each degree C the temp goes up.  V = 331 
m/s + 0.6(t C).
	  It travels 4 times faster in water and 15 times faster in steel.

     PROPERTIES OF SOUND:

	  Intensity is the ratio of power to area   I = P/A (watts/cm2).

	  Intensity is proportional to the square of the amplitude.

	  Intensity obeys the inverse square law.  Twice as far away, the 
intensity is only 1/4 a s great.

	  Loudness depends on an auditory sensation in the 
consciousness of a listener.  It is a subjective property.

	  Relative intensity measurements are done on a logarithmic 
scale called the DECIBEL SCALE. On this scale the threshold of 
hearing is 0, whispers are 15, conversation is 60, thunder is 110, the 
threshold of pain is 120, jet engine is 170, rock band 180 (just 
kidding).

     PITCH is the highness or lowness of a tone and it depends upon 
frequency (the number of cycles/sec).  The higher the frequency, 
the higher the pitch.

     THE DOPPLER EFFECT is the change in pitch due to relative 
motion between the source and the listener. When the listener 
approaches the sound source, he runs into more waves/sec, and 
hence the pitch is increased, when the source approaches the 
listener, waves are crowded together so the pitch is increased. 
Likewise, when the distance between source and listener is
increased, the pitch drops. A typical example is the passing of a 
car... EEEEEEEAAAAaaooow.

     CHARACTERISTICS OF SOUND WAVES--

	  Standing waves are resonant waves with nodes and antinodes.  
The fundamental or first harmonic consists of one antinode with a 
node at each end.  The second harmonic has two antinodes, etc. See  
p 266 in the text for diagrams.

	  Harmonics may be superimposed upon other harmonics to 
produce musical tones.

	  The Quality of sound is that which differentiates the sound of 
one instrument from another even when they are playing the same 
pitch. A tone is determined by the number and strengths of the 
harmonics.  See text for illustrations.

	  The Beat Frequency is the pitch caused by the interference of 
two sound waves of different frequencies undergoing constructive 
and destructive interference.  It varies in loudness so that it is a 
throbbing sound. When two tones are in tune, there will be no beats.   
See p 276 for diagram.

	  The Laws of Strings--

	       Law of Lengths states that the frequency is inversely 
proportional the length. The longer string has a lower pitch.

	       Law of Diameters is that frequency is inversely 
proportional to the diameter. The larger the diameter, the lower the 
pitch.

	       Law of Tensions states that the frequency is directly 
proportional to the square root of the tension. The higher the 
tension, the higher the pitch.

	       Law of Densities is that the frequency is inversely 
proportional to the square root of the density. The greater the 
density, the lower the pitch.


     RESONANCE is the reinforcing of waves of the same frequency 
which are in phase. Standing waves are produced.  A fun example 
(when no one is around) is to step on the damper pedal of a piano 
and scream into the thing.  It screams back in resonance. See text for 
diagrams.

	  An open tube resonator (open organ pipe) has an antinode at 
each end. The result is that it resonates the even numbered 
harmonics.

	  A closed tube resonator (closed organ pipe) has a node at one 
and an antinode at the other.  It resonates odd numbered 
harmonics.  See diagrams in the text.

	  Formulas for resonant pipes are in the text .

LIGHT:

     The corpuscular (particle) theory of Newton states that light is 
composed of particles.

     The wave theory of Huygens states that light is composed of 
waves. Light waves are transverse waves composed of crests and 
troughs.  (Sound waves are longitudinal).

     We need both theories to explain all the phenomenon of light.  
Whenever a tiny particle moves at high speed, it assumes wave 
properties.

     Photons are the particles (with wave properties) of light.  Each 
photon is a quantum of energy.

     The electromagnetic theory states that light photons are waves 
with two components at right angles to each other.  The electric field 
and the magnetic field are the components.


PROPERTIES OF LIGHT:

     RECTILINEAR PROPAGATION.  Like all waves, the wave front 
spreads out in straight lines from the origin.

     REFLECTION.  The angle of incidence equals the angle of 
reflection.  The angles are measured from the NORMAL to the 
surface.

     REFRACTION is the bending of light as it changes media at an 
angle.  It is due to the fact that light travels more slowly in denser 
media.

     DIFFRACTION is the spreading out of light waves as they pass 
around objects.

     THE PHOTOELECTRIC EFFECT.  When light strikes a substances 
with sufficient energy, electrons are emitted by the substance.  An 
example is the photoelectric cell or the "electric eye".

     THE QUANTUM THEORY explains the photoelectric effect. The 
energy of the emitted electrons depends on the frequency of the 
light photon.  The number of electrons emitted depends on the 
intensity of the light.

     PLANK'S EQUATION is  E = hf  where E is the energy of the 
emitted electron, f is the frequency of the light waves, and h is 
Plank's Constant, 6 X 10-34 js (the quantum of energy).

     THE QUANTIZED ATOM.  The above quantum effects coupled 
with the discrete spectral lines emitted by stimulated atoms, led to 
the orbital model of the atom with electrons spreading out to fill 
quantum energy levels about the nucleus of the atom. Whenever an 
electron changes energy levels (orbitals), photons of light are 
absorbed or emitted.  This gives the special spectral lines associated 
with each element.  See color plate VII about p 337.

     THE LASER (Light Amplification by Stimulated Emission of 
Radiation), is the result of raising electrons to higher energy levels 
by applying a burst of energy (say by intense light, electrical charge, 
or chemical reaction).  The energetic electrons drop back to their 
lower energy levels simultaneously when stimulated
by photons reflecting back and forth between mirrors.  This gives a 
coherent burst of pure light (the waves are in phase to give massive 
constructive interference).

     PRESSURE OF LIGHT.  Light exerts a force per area which is equal 
to 4 X 10-11 atmospheres.  It is sufficient to push forth the tails of 
comets (along with other solar radiation).

     ILLUMINATION--

	  Luminous is the property of a substance to emit light by 
virtue of accelerated particles. Particles are accelerated by electric 
stimulation or by high temperature. Examples are stars, heated 
objects, and electric discharges.

	  Illumination is the receiving of light from another source. An 
object which can be both luminous and illuminated is a light bulb.

	  Intensity is the strength of light emitted.  It is measured in 
candles, cd.

	  Illumination depends upon both intensity and distance (the 
inverse square law).  Its unit is the lumen.  One lumen is the amount 
of light received on the interior surface of sphere one meter in area 
at a distance of one meter from a one candle source.    The formula 
for illumination is  E = I/r2  where is E is in lumens, I is in candles, 
and r is in meters.  See sample probs  in text.

	  The Seasons on Earth are caused by the variation of the angle 
of incidence of the sun's rays due to the tilt of the earth's axis (23.5 
deg).  See diagrams in text.

	  The Speed of Light is 300,000 Km/s, 3 X 108m/s. See text 
diagrams for the Michelson's method using a rotating mirror and 
the formula d = rt.

	  The Umbra is the total dark shadow of the earth and the 
moon.

	  The Moon is eclipsed when it is in the Earth's umbra.

	  The Sun is eclipsed when we are in the Moon's umbra.

	  The Penumbra is the partial shadow of the earth or the moon.

	  Partial eclipses involve the penumbra. See text for diagrams.

	  The Inverse Square Law applies to all forms of energy that 
radiate such as light, sound, gravity, magnetism, and electric fields. 
See text for diagram of the inverse square law.


     REFLECTION:

	  Regular reflection is caused by smooth surfaces so that the 
reflected rays are parallel.

	  Diffuse reflection is caused by irregular surfaces such that the 
reflected rays are not parallel.

	  Law of reflection-- The angle in incidence is equal to the angle 
of reflection.  The angles are measured from the line drawn normal 
to the surface at the point of contact. These three parts are all in the 
same plane.

	  MIRRORS--

	       Plane mirrors are flat and images appear as far behind 
them as the objects are in front of them.

	       Concave curves inward.  It is a converging reflector as 
parallel rays come to a focus.

	       Convex curves outward (like the middle of the Boom).  It 
will cause parallel rays to diverge.

	       Mirror diagrams and formulas are found amongst  the text
		      They're important so check 'em out.

     REFRACTION:

	  Refraction is the bending of light as it passes from one 
medium into another due to its change in speed

	  The Index of Refraction is the ratio of the speed of light in 
vacuum to the speed of light in the medium.

	  Snell's Law states that the index of refraction is also equal to 
the ratio of the sine of the angle of incidence to the sine of the angle 
of refraction. The angles are measured from the normal drawn to 
the surface.

	       n = sin i/sin r  where n is the index of refraction.

	  See diagrams in text.

     LENS OPTICS:

	  Converging lenses are thicker (avoid the term fatter) in the 
center. They cause parallel rays to pass through a focal point.

	  Diverging lenses are thinner in the middle. They cause 
parallel rays to spread out.

	  See types of lenses in text.

	  Rules and diagrams for constructing and calculating lens 
situations are important. See text.


     DISPERSION:

	  Dispersion is the spreading of white light into its spectrum of 
colors. ROY G BIV.  It is caused by the fact that light of different 
wave lengths is refracted by different amounts.  The red end of the 
spectrum bends the least.

	  Primary Colors of Light are red, green, and blue. These three 
join to make white light. The primaries of light ADD to make 
resultant colors.

	  Complementary Colors are two colors that join to make white 
light. One of the complements already contains two primaries.

	  Primary Colors of Pigment (paint) are cyan, magenta, and 
yellow.  They SUBTRACT light by absorption. The three primaries of 
pigment produce black when mixed as they absorb all the light.

	  See the color plates beginning after p 336.

	  Chromatic Aberration is the distortion and separation of 
colors by the fact that different colors are refracted differently by 
uncorrected lenses. See p 360 for diagram and what to do about it.

     DIFFRACTION:

	  Diffraction is the spreading out of light as passes around 
sharp objects or through narrow slits. See diag p 363.

	  Interference is the inter-reaction of light waves.

	       Constructive interference is the adding of light waves crest 
to crest and trough to trough.

	       Destructive interference is the adding of light waves crest 
to trough so that there is cancellation.

	       Two interacting light waves out of phase will give 
interference patterns. See Thin Film interference p 364 for 
explanation of soap bubble and oil slick colors. Also bird feathers 
are colored by this method.

	       The Diffraction Grating is a transparent surface having 
several thousand lines per centimeter etched thereon.  It will 
produce spectra of white light or line spectra for stimulated gases. 
(The prism does this by refraction).    Spectra are produced because 
different wavelengths are diffracted different amounts.  See text.

     THE DOPPLER EFFECT for light is the change in frequency (color) 
of light due to relative motion between the source and observer. 
Approaching gives blue shifts, and receding gives redshifts.  
Remember that higher frequency is bluer light, and approaching 
sources crowd waves more closely together to increase the 
frequency.

	       The relative velocity of stars and galaxies can be 
determined by the blue or red shifts of their light.  The shift is a 
comparison of spectral lines of the star to the lines of the same 
elements in the laboratory.

     POLARIZATION is the process of the light waves vibrating in the 
same plane.  This is accomplished by certain crystals or by 
reflection of light at certain angles.  See text.

     SCATTERING OF LIGHT is caused by small particles such as 
molecules or very tiny dust particles. The particles are a size about 
the same as the wavelength of the light being scattered.

     BLUE SKY AND DEEP WATER are colored by the scattering of the 
blue light which has a short wave length.  The longer red waves 
diffract around the particles in the atmosphere and travel a long 
distance.
	  Hence, during the day when the sun is high in the sky, 
the rays travel a short distance down through the atmosphere (a few 
hundred kilometers) and so not much blue light is scattered out.

     RED SUNSETS AND SUNRISES are caused by the scattering of the 
short wave length blue light.  This leaves the longer red waves to 
traverse the atmosphere to the observer over the horizon.
	Hence, at sunrise and sunset, the rays are traveling a 
great distance through the atmosphere (thousands of kilometers) so 
most of the blue is scattered out and mainly the red remains.  See 
Text diagrams.


				***  ELECTRICAL ACTION  ***


      
ELECTRICAL TERMS:
  
     Negative charge--  An excess of electrons.
     Positive charge--   A deficiency of electrons.
     Neutral charge--   The number of electrons equals the number of 
				  protons.  
     Electroscope--       A device for detecting electric charge.  It has a
				  pair of metal foil leaves that are pushed apart
				  by electric force fields.
    Coulomb's Law--    The force between charges varies directly as
				  the product of the charges and inversely as
				  square of the distance between the charges.
				  F = k (Q Q)/d2.
     DC--                      Direct current.  The electrons flow in one
				  direction only.  Negative to positive.
     AC--                      Alternating current.  The flow of electrons
				   reverses at a steady rate. (i.e. 60 cycles/sec).
     Conductor--           A substance (usually metal) that has loose
				   electrons (partially filled orbitals).
     Insulator--             A substance (usually a non-metal) that has
				  no free electrons.
    Ohm's Law--          The current (amps) is directly proportional
				  to the emf (volts) and inversely proportional
				  the resistance (ohms).
				   I = V/R. 
     Solenoid--             A coil of wire for concentrating magnetic field.
				  With a moveable permeable core, it can 
				  operate mechanical devices.
     Capacitor--            A device for storing electric charges.  Two 
				  conductors separated by an insulator (the
				  dielectric).
     Induction--            The process of producing a current in a 
				    conductor by moving it through a magnetic 
				    field. The field must be cut.
     Inductor--              A coil of wire whose purpose is to cause an
				   impedance (inductive reactance) to
				   alternating current flow.
     Inductive
	  reactance--       The opposition to current flow caused by the
				    self-induction of opposing currents in coils.
				    Coils oppose high frequency AC and have
				     low reactance to DC.
     Lenz' Law--            An induced current has such a direction that
				   its magnetic field opposes the field which
				   induced it.
     Choke coil--           An inductor.  It resists AC while passing DC.

     Capacitive
	   reactance--       The opposition to current flow caused by a
				    capacitor.  Capacitors are open circuits to
				    DC.  High frequency AC appears to pass
				    through a capacitor.
     Impedance--          The combined opposition to current flow  due
				   to resistance, inductive reactance, and 
				   capacitive reactance.  It is a vector sum 
				   wherein the inductive reactance acts upward, 
				   the capacitive reactance acts downward, and 
				   the resistance acts sideways.
    Angle of lag
	or lead--              The angle caused by the impedance vector
				    measured from the resistance vector.  It 
				    shows the phase relationship in an AC circuit.
    Power factor--          The cosine of the angle of lag or lead.
    Ohm's Law for
	  AC  circuits--    Current = volts/impedance.  I = V/Z.
    Power in AC
	  circuits--           Power = (volts)(amps)(power factor).
    Resonance--            The resonant frequency of an AC circuit
				    is the frequency at which the inductive
				    reactance equals the capacitive reactance.
				    At this frequency the two reactances cancel
				    and the circuit acts as though is contains
				    resistance only.  This enables us to select
				    certain frequencies. (i.e. to tune radio and
				    and television stations.
     Electrolyte--         A solution that conducts electricity.  It contains
				  ions. (Acids, bases, salts).
     Cell--                    Two unlike conductors in an electrolyte. 
				  Produces an emf (voltage).
     Battery--               A group of cells connected together change
				  voltage or current capacity.
     Commutator--      A split ring on the shaft of a motor or a
				 generator that mechanically reverses the
				 wires as the rotor turns.  It keeps a motor
				 turning and will change a generator's AC to DC.
     Slip rings--           The rotating connection on the shaft of a 
				  generator that contacts the brushes to remove
				  the current from the rotor.
    Series circuit--       Components connected such that tall of the 
				  current must pass through each component.
    Parallel circuit--    Components are connected such that the
				  current will divide between them.
    Thermocouple--    Two unlike metals joined.  When the junction
				  is heated, an emf is produced.
    Electrode--             A conductor placed into a solution or a
				   vacuum tube. (or Frankinstein's temple).
    Anode--                  Usually the positive electrode.
    Cathode--               Usually the negative electrode.
    Thermionic 
	  emission--       A heated cathode boils off electrons. Source of
				  electrons in vacuum tubes.
   D'Arsenval meter
	 movement--      The mechanism of springs, magnets and coils 
				     that operate electric meters.
    Galvanometer--     A meter for measuring very small currents.
    Voltmeter--           A high resistance galvanometer for measuring
				 emf.  It's connected in parallel with the load.
    Ammeter--            A low resistance galvanometer for measuring
				 current flow.  It's connected in series with the
				 load.
    Watt meter--         A combination volt and ammeter for 
				  measuring electric power.
    Watt hour meter-- A recording meter for keeping a record of
				  electrical energy consumed. (Found on 
				  houses).
    Resistance--           The friction to electron flow in a conductor.
    Resistor--               A device for limiting electron flow.
    Rheostat--              A variable resistor.
    Potentiometer--     A variable resistor that can reverse current
				  direction as well as very the resistance.
   Wheatstone
	  Bridge--           A device for accurately measuring resistance.
   Electrolysis--          The decomposition of substances by passing an
				  electric current through their melts or 
				  solutions.
   Permeability--         The ability to conduct a magnetic field. Iron is
				  very permeable.
   Electromagnet--      A coil of current-carrying wire wrapped 
				  around a permeable core.
  Magnetic domains-- Groups of atoms adding their magnetic fields.
				     Lining up the domains magnetizes a piece of
				     metal.


ELECTRICAL UNITS:

     Coulomb-- Unit of electric charge.  Is equal to 6 X 10 to the 18th 
		       electrons.
     Ampere--   Rate of current flow. Is equal to 1 coulomb per
		       second.
     Volt--         Unit of electrical pressure (potential difference)
		       Will do a joule of work per coulomb of charge, 
		       V = J/c.   Emf (electromotive force) is volts.
     Ohm--        Unit of electrical resistance.  Is equal to the resistance 
		       of a 1 meter column of mercury, 1 mm cross-sectional 
		       area at 0 deg C.  Or one volt per ampere.
     Mho--         Unit of conductance.  The reciprocal of the
		       resistance.
     Watt--        Unit of power. Equal to one joule/sec or volts X amps. 
		       P = VI.
     Farad--      Unit of  capacity of a capacitor.  Will take a charge of 
		      one coulomb per one volt of emf.  C = Q/V where C is
		      the capacitance in farads, Q is the charge in coulombs, 
		       and V is the emf in volts.
     Henry--     Unit of inductance.  A coil has an inductance of 1 h 
		      when a current changing at the rate of one ampere
		      per second induces a back emf of one volt.

  


			     *** ATOMIC STRUCTURE ***
					      and
		      The Discovery of Sub-Atomic Particles

ATOMIC THEORIES:             
	Democritus (Ancient)
	Dalton (Modern)

LAW OF CONSERVATION OF MASS  
	The Total Mass Entering a chemical reaction = the total mass 
leaving the reaction.

LAW OF DEFINITE PROPORTIONS (Dalton's Law)
	Every compound has a definite ratio of elements by mass.   
		     (Ah... Formulae!)

LAW OF MULTIPLE PROPORTIONS
	Some compounds exhibit whole number ratios of elements.

		H2O, H2O2, NO, N2O, N2O3, N3O4, FeO, Fe2O3, Fe3O4

THE LAW OF GAY LUSSAC
	The combining ratios in reactions are of small whole numbers.

The Above Laws indicate that there are basic particles (atoms) that \
	    make up matter.

FARADAY'S DISCOVERY--
	Electricity decomposes compounds into elements.  On 
	   re-forming, electricity is re-generated.
	This shows that the binding force between atoms in a 
	   compound is electrical. 

THE DISCOVERY OF PARTS OF THE ATOM  (Late 19th and early 20th 
      century action)--
	The high voltage Induction Coil, "Sparky" gave the energy 
	     needed to probe the atom.
	Discharge Tubes-- lowering air pressure in a tube allowed the 
	 "Cathode Rays" to travel great distances (many meters).

										  
	
THE DISCOVERY OF THE ELECTRON--

		The Tube of Sir William Crookes--
										
		The Rays--
			travel from Cathode (negative) to Anode (positive). 
				 hence they are NEGATIVE.
			are easily stopped by thin metal obstacles (the Iron 
			       Cross).
			    travel in Rectilinear Propagation because 
			       the shadow of the cross is sharp. 
			    they are attracted to positive electric charges and 
				repelled by negative charges placed beside the 
				     tube. 
			     are bent at right angles by magnet fields.
			   cause fluorescence on the glass and upon certain
				 minerals.

THE DISCOVERY OF THE MOMENTUM OF THE RAYS--
				
	     The Paddle Wheel Tube (the tube of Jean Perrin) showed 
		  that the Cathode Rays have mass and velocity  
		(momentum)  because they push the paddles. 
		  Great fluorescent colors are demonstrated by paint
		   on the paddles.
			The rays therefore must be particles and were 
			    named "Electrons".  
			
THE MEASUREMENT OF THE CHARGE TO MASS RATIO OF 
	 ELECTRONS--

The Tube of Sir JJ Thompson--

     The candy cane-shaped tube bent the cathode rays in a magnetic 
	 field and showed their path on a fluorescent screen. This 
	 enabled the calculation of the Charge to Mass Ratio. Higher 
	 charge would bend the beam more, higher mass would bend 
	 the beam less.

		e/m = ratio = 1.8 X 10t o the 8th  coulomb/gram.

THE DETERMINATION OF THE CHARGE OF THE ELECTRON--

	Millikan Oil Drop Experiment to measure the actual charge on 
	  an electron. X-Rays would add or subtract  electrons to the 
	  microscopic droplets.  By varying the electric charge needed
	  to balance the weight of the droplet, three 
	   biggies were discovered:
	     1. All electrons are identical.
	    2. The electron is a basic particle of electricity.
	    3. The charge of the electron, e = 1.6 X 10-19 coulomb (c) of 
		  charge.

THE CALCULATION OF THE MASS OF THE ELECTRON--

	  The Mass of the electron is determined from e/m ratio and 
	    the charge:

	     e/m = ratio , so m = e/ratio , hence: m = 1.6 X 10-19c /1.8 
	      X 10 to the 8th c/g

		 m = 9.11 X 10-29   gram/electron  WOW!  That's tiny!

THE DISCOVERY OF IONS AND THE PROTON--

     The Canal Ray tube was built to see if there are rays from the 
	 anode.  There were positive rays, but not from the anode. 
     They were produced by the impact of electrons with atoms of gas 
	 in the tube.

      The Canal Ray Tube
				   
	    The collisions knocked electrons off the atoms creating 
		positive IONS. The e/m ratios of the ions (in a JJ tube) 
	       depended on which gas was used.  When using the 
		simplest gas, Hydrogen, we found the simplest ion, the 
	       Hydrogen nucleus called the "PROTON".
									 
THE DISCOVERY OF ISOTOPES--
		
     The Mass Spectroscope is a refined Sir JJ tube built for accurate 
	 measurements. When ions were sent through it, they separated 
	 into several beams according to different masses (their  
	 charges were the same). These different masses for the same 
	 element were called "ISOTOPES" (in the same place on the
	 periodic table).

					
THE DISCOVERY OF THE NEUTRON--  

	To explain ISOTOPES we postulated a NEUTRAL particle whose 
	     mass was equal to that of the Proton.  This way we could 
	     account for a change in mass without  changing which 
	     element was present.

	The Neutron was discovered in 1932 by Chadwick using a 
	     piece of jam jar paraffin to react with radiation.
		

THE DISCOVERY OF X-RAYS--

     Roentgen was experimenting with discharge tubes and found 
	fluorescent substances were glowing around in his lab
	 including places behind barriers. Powerful!  
	They are created when electrons strike a metal target.
	X-rays are electromagnetic waves above the Ultra-Violet on the 
	     spectrum.

		X-rays are used to determine:
			The Atomic Number (the number of protons in the
			       nucleus. The wave length of X-rays depends on
			       number of protons).
			The Structure of crystals  (X-ray diffraction 
			       studies).


 THE DISCOVERY OF RADIOACTIVITY AND ITS THREE RAYS--
		
	Becquerel, experimenting with fluorescent minerals, found 
	      that Uranium ore on his desktop exposed film in the
	      drawers below with the shadow of a key thereon.
						 
	 Marie Curie analyzed Uranium ore and discovered new 
	      radioactive elements including Radium.

	 Lord Rutherford, using Marie's Radium, found three rays 
	     coming therefrom:
				
		Alpha rays-- Positive Helium ions.  Small deflection due 
		       to high mass.
		Beta rays--  Electrons.  Large deflection due to very low 
		       mass.
		Gamma rays-- Electromagnetic waves of very high energy 
		       ... WOW! 
				
		Properties of Radioactivity:
				Cause ionization.
				Discharge electroscope.
				Cause fluorescence.
				Expose photographic film.
				Destroy cells. 
				Promote nuclear reactions.


THE SIZE OF THE ATOM--

	For Copper, weigh out 1 mole-- 63.5 g/mol.
		Make it into a cube.  Ah, it's 2 cm per side.
		This cube contains 6 X 10 to the 23rd atoms (1 mol)
		To find the number of atoms per side of the cube, take 
		      the cube root of 6 X 10 to the 23rd.  It's about 
		      10 to the 8th atoms per side.
		Now divide the 2 cm per side by the 10 to the 8 th atoms
		      per side, and you get about 10-8 cm per atom.
		     This is called the Angstrom unit (the size of an atom).
			  
						   

THE SIZE OF THE NUCLEUS--

	  Lord Rutherford shoots Alpha Particles (Helium nuclei)
	      through a thin piece of gold foil.
	       SHOCK! most Alphas go right on through. Hence the atom
		 must be mostly empty space!
			
	A very few Alphas are deflected however.  From the statistics 
	      of the deflection patterns, the size of the nucleus is 
	      calculated. About 10-13 cm diameter! 

      Compared to the size of the atom (10-8 cm), the nucleus is 
	  "The flea in Yankee Stadium".

DISCOVERY OF THE ORBITALS OF THE ELECTRONS:

	  Spectroscopy--
	       When electrical discharge is sent through gases in a 
		 tube, and the light emitted passed through a prism, we 
		 get a spectrum of bright lines. These lines are the spectral 
		 "finger prints of the atom" From the line spectra we learn
		   Which elements are present (like in the stars).
		   The arrangement of electrons around the nucleus, 
			  called the Electronic Configuration.          
			
NUCLEAR REACTIONS--
	Top numbers are the mass numbers (protons + neutrons).
	Bottom numbers are the charge numbers (atomic numbers).
	The sum of the numbers on the right must equal the sum of 
	      the numbers on the left.

    2He4   +   4Be9   --->   6C12   +   0n1

TRANSMUTATION--

     0n1   +   92U238   --->   93Np239  +   -1 e 0

NUCLEAR FISSION  & THE CHAIN REACTION--

 92U235   + 0n1   --->  56Ba141   +  36Kr92  +  3 0n1  +   ENERGY!!



			  ***  HERE ENDETH THE NOTES  ***

