Index
Periodic Table Help Index

Introduction

Customizing the main window

Showing detail

Supplementary data

Future enhancements

Bibliography

Glossary


Introduction

This program was written to collect in one place a wide selection of information about the elements, and make the data easy to access and cross-reference.

This program has been used by researchers and scientists for reference purposes.  It is also useful to students and others wishing to learn about the chemical elements.


Customizing the main window

The Display menu allows you to select which items you wish to display on the main window.

Use Color	When selected, color indicates the state of matter for each element at 300K.

Colors...	This allows you to customize the colors used for indicating state of matter.  Select the state of matter, then use the scroll bars to select a color.

Atomic Symbol	Display the atomic symbol for each element, if there is room.

Atomic Number	Display the atomic number for each element, if there is room.

Group Headings	Display the group heading for each column.

IUPAC	Display group headings and atomic symbols conforming to those recommended by the International Union of Pure and Applied Chemistry.

American	Display group headings and atomic symbols following American chemistry traditions.

Save Setup	Save colors, defaults, and display options.

The main window can be sized as desired.  If the table becomes too small to display the selected text, the text is omitted.


Showing detail

Click on an element to see an element detail box.

The upper half of the detail box displays

Element Name	The commonly used name of the element.  The names of a few elements are disputed.  The periodic table program displays either the IUPAC name or the traditional American name.

Atomic Symbol	The one- or two-letter abbreviation for an element, commonly used in chemical formulas.

Atomic Number	The number of protons in the atomic nucleus.

Atomic Weight	The mass of a neutral atom of a nuclide, expressed in atomic mass units.  One atomic mass unit is defined as one-twelfth of the mass of an atom of Carbon-12.

Density	Mass per unit volume.

Boiling Point	The temperature at which a substance changes from liquid state to gaseous state.

Melting Point	The temperature at which a substance changes from solid state to liquid state.

The lower half shows additional information from one of several categories.  When the element detail box is first opened, the Defaults menu item dictates which set appears first.   Subsequently, the category may be changed by selecting one of the buttons.

Thermodynamic Properties

Isotopes

Ionization Potentials

Chemical Properties

General Information

Unless otherwise stated, the data is for the element at 298K and 1 atm.  For those elements for which more than one form commonly exists, the data is given for the most stable form.


Supplementary data

Choose the Constants menu item under Supplementary to display a table of commonly used physical constants.

Avogadro's Number	The number of molecules in one mole or gram-molecular weight of a substance.

Permeability of Vacuum	Also called permeability of free space.  The ratio of the magnetic induction of a vacuum to the magnetizing field to which it is subjected.

Speed of Light	The propagation rate of photons in a vacuum.

Elementary Charge	The electric charge of one electron or proton.

Planck's Constant	The ratio of the energy of a quantum of radiation to its frequency.

Electron Rest Mass	The mass of an electron at absolute rest.

Proton Rest Mass	The mass of a proton at absolute rest.

Neutron Rest Mass	The mass of a neutron at absolute rest.

Gas Constant	The constant factor R in the equation of state for perfect gases.

Boltzmann's Constant	The ratio of the universal gas constant to Avogadro's number.  Also called "gas constant per mole".

Gravitational Constant	The coefficient of proportionality in Newton's Law of Gravitation.


Future enhancements

Your $20 ($95 for source code) registration entitles you to receive notice of the next Periodic Table update when it is available, as well as free copies of several other science-related programs.

Likely features in the next version:

>	Graphing capability for any of the numeric data

>	Copy-to-clipboard as text

>	Color parameter selection on any numeric data

>	Full keyboard support

>	Corrections to data

>	Additional data

>	User suggestions

Please send other suggestions for improving this program or any other comments you may have.

Ernest L. Edgar

26851 NW Williams Canyon Rd.

Gaston, OR  97119


Bibliography

Element data has been taken from the following sources.  We have tried to resolve discrepancies where possible.

Carmichael, Robert S., CRC Practical Handbook of Physical Properties of Rocks and Minerals, CRC Press, Boca Raton, Florida, 1989.

Emsley, John, The Elements, 2nd ed., Oxford University Press, New York, 1991.

Holden, Norman E., and Walker, F. William,  Chart of the Nuclides, 10th ed.,  U.S. Atomic Energy Commission, 1968.

Moses, A.J., The Practicing Scientist's Handbook, Van Nostrand Reinhold, New York, 1978.

Sargent-Welch Scientific Company, Periodic Table of the Elements, 1979.

Weast, Robert C., (ed.), CRC Handbook of Chemistry and Physics, CRC Press, Boca Raton, Florida.


Glossary

A-B

Atomic Mass Unit

Atomic Number

Atomic Radius

Atomic Symbol

Atomic Volume

Atomic Weight

Avogadro's Number

Boiling Point

Boltzmann's Constant

C-D

Covalent Radius

Crystal Structure

Decay

Density

Discoverer

E-F

Electrical Resistivity

Electron Configuration

Electronegativity

Electron Rest Mass

Elementary Charge

Element Name

Entropy

G-H

Gas Constant

Gravitational Constant

Halflife

Heat Capacity

Heat of Fusion

Heat of Vaporization

I-J

Ionic Radius

Ionization potential

K-L-M-N

Melting Point

Natural Abundance

Neutron Cross Section

Neutron Rest Mass

O-P

Pauling's Electronegativity

Permeability of Vacuum

Photoelectric Work Function

Planck's Constant

ppm, Earth Crust

ppm, Chondrites

ppm, Cosmic

Proton Rest Mass

Q-Z

Speed of Light

Thermal Conductivity

Thermal Expansion Coefficient

Toxicity


  Thermodynamic Properties

Thermodynamic properties of elements can be used to predict the outcomes of chemical reactions.  Generally, reactions proceed toward the state with the lowest energy.

Heat of Fusion	The quantity of heat required to change one mole of a substance from solid state to liquid state at the melting point.

Heat of Vaporization	The quantity of heat required to change one mole of a substance from liquid state to gaseous state at the boiling point.

Heat Capacity	The quantity of heat required to increase the temperature of one mole of a substance by one degree Kelvin.

Entropy	A measure of the extent to which the energy of a system is unavailable.  Sometimes referred to as "the degree of disorder of a system".  The entropy values given are Standard Entropy, the entropy of the element at 298.15K, 1 atm.

Atomic Volume	The space occupied by one mole of an element.

Thermal Conductivity	The rate of transfer of heat by conduction in a substance.

Electrical Resistivity	The resistance of a substance to electrical current flow.

Photoelectric Work Function	The energy required for an electron to escape a solid surface.

Thermal Expansion Coefficient	The proportion by which a substance expands linearly with increasing temperature.


  Isotopes

Each element has a number of different forms called isotopes.  These are listed in ascending atomic weight order.  Naturally occurring isotopes are shown in red on color monitors.  Information about each isotope listed includes:

Atomic Weight	The mass of a neutral atom of a nuclide, expressed in atomic mass units.  For pure isotopes, the atomic weight rounded to the nearest integer is the sum of the number of protons and neutrons found in the nucleus.

Natural Abundance	The percentage of a particular isotope in the naturally occurring element.

Halflife	The average time required for one half of the atoms in a radioactive sample to decay.

Decay	The diminution of a radioactive isotope due to nuclear emission of alpha particles, beta particles, gamma rays, or positrons, or by electron capture, isomeric transition, or spontaneous fission.

Using the decay mode information, you can follow the sequence of decay of any element until it reaches a stable isotope.

Atomic	Atomic

Decay Process	Number	Weight

neutron	0	-1

proton	-1	-1

alpha particle	-2	-4

beta particle	+1	0

positron	-1	0

electron capture	-1	0

Example: the decay path for U-238:

92	U	238	alpha

90	Th	234	beta

91	Pa	234	beta

92	U	234	alpha

90	Th	230	alpha

88	Ra	226	alpha

86	Rn	222	alpha

84	Po	218	alpha

82	Pb	214	beta

83	Bi	214	beta

84	Po	214	alpha

82	Pb	210	beta

83	Bi	210	alpha

81	Tl	206	beta

82	Pb	206	(stable)


Ion Potentials

  Ionization Potentials

This window displays a list of the known ionization potentials.

This information can be used to determine the tendency of an element to form particular ions.  For example, the first few ionization potentials of sodium,

+1	5.139 eV

+2	47.286

+3	71.64

indicate that sodium is very prone to losing one electron (Na+) and forming univalent compounds with negatively charged ions, such as Cl-, but is extremely unlikely to lose two electrons to form, for example, NaO.


  Chemical Properties

Electron Configuration	The distribution of electrons in orbitals, or shells around the nucleus.  The configuration of the outermost shell of electrons heavily influences the chemical properties of the element.

Pauling's Electronegativity	A measure of the electron affinity of an atom.  The difference in electronegativity of two elements forming a compound indicates the tendency toward ionic as opposed to covalent bonding character.

Neutron Cross Section	A measure of the probability of collision between the nucleus and a slow-moving neutron.

Atomic Radius	The effective size of a free atom.

Covalent Radius	The effective size of an atom when covalently bonded.

Ionic Radius	The effective size of a charged atom in an ionic compound.  The relative sizes of ionic radii in an ionic compound determines the compound's crystal structure.

Crystal Structure	The arrangement of atoms of the pure element when in the solid state.


  General Information

Year of Discovery	The year when the element was first observed.  This may be different from the time when the element was first isolated.

Discoverer	The person credited with the discovery of the element.

Origin of Name	The etymology of the element name.

ppm, Earth Crust	Proportion of element in the outer lithosphere.  This includes most of the solid shell of rock, but does not include the atmosphere or ocean.

ppm, Chondrites	Proportion of element in carbonaceous chondrite I meteorites.  This concentration is widely considered to be representative of the solar system at the time of its formation.

ppm, Cosmic	Proportion of element in the visible universe.  Obtained from astronomical spectra.

Approximate Cost	A very rough measure of the scarcity of the pure element.

Principal Sources	Naturally occurring minerals or compounds containing the element.  For synthetic elements, the method of synthesis is given.

Principal Uses	Major modern industries which use the element.

Properties	Gross physical properties such as appearance, ductility, etc.

Toxicity	A rough indicator of the element's harmful potential.


 Element Detail Box

The element detail box is a window which displays information about an element.  The window can be moved, minimized, and closed.  Several element detail boxes can be open simultaneously.


 Element Name

The commonly used name of the element.  The names of a few elements are disputed.  The periodic table program displays either the IUPAC name or the traditional American name.


 Atomic Number

The number of protons in the atomic nucleus.


 Atomic Symbol

The one- or two-letter abbreviation for an element, commonly used in chemical formulas.


 Atomic Weight

The mass of a neutral atom of a nuclide, expressed in atomic mass units.  One atomic mass unit is defined as one-twelfth of the mass of an atom of Carbon-12.  For pure isotopes, the atomic weight rounded to the nearest integer is the sum of the number of protons and neutrons found in the nucleus.


 Atomic Mass Unit

One-twelfth of the mass of an atom of Carbon-12.


 Density

Mass per unit volume.


 Melting Point

The temperature at which a substance changes from solid state to liquid state.


 Boiling Point

The temperature at which a substance changes from liquid state to gaseous state.


 Avogadro's Number

The number of molecules in one mole or gram-molecular weight of a substance.


 Permeability of Vacuum

Also called permeability of free space.  The ratio of the magnetic induction of a vacuum to the magnetizing field to which it is subjected.

B = µ0H


 Speed of Light

The propagation rate of photons in a vacuum.


 Elementary Charge

The electric charge of one electron or proton.


 Planck's Constant

The ratio of the energy of a quantum of radiation to its frequency.

E = hv


 Electron Rest Mass

The mass of an electron at absolute rest.


 Proton Rest Mass

The mass of a proton at absolute rest.


 Neutron Rest Mass

The mass of a neutron at absolute rest.


 Gas Constant

The constant factor R in the equation of state for perfect gases.

PV = nRT

P = pressure

V = volume

n = amount of gas in moles

T = temperature


 Boltzmann's Constant

The ratio of the universal gas constant to Avogadro's number.  Also called "gas constant per mole".


 Gravitational Constant

The coefficient of proportionality in Newton's Law of Gravitation.


 Heat of Fusion

The quantity of heat required to change one mole of a substance from solid state to liquid state at the melting point.


 Heat of Vaporization

The quantity of heat required to change one mole of a substance from liquid state to gaseous state at the boiling point.


 Heat Capacity

The quantity of heat required to increase the temperature of one mole of a substance by one degree Kelvin.


 Entropy

A measure of the extent to which the energy of a system is unavailable.  Sometimes referred to as "the degree of disorder of a system".  The entropy values given are Standard Entropy, the entropy of the element at 298.15K, 1 atm.

The third law of Thermodynamics states

The entropy of a pure, perfectly crystalline substance is zero at the absolute zero of temperature.


 Atomic Volume

The space occupied by one mole of an element.


 Thermal Conductivity

The rate of transfer of heat by conduction in a substance.


 Electrical Resistivity

The resistance of a substance to electrical current flow.


 Photoelectric Work Function

The energy required for an electron to escape a solid surface.


 Thermal Expansion Coefficient

The proportion by which a substance expands linearly with increasing temperature.


 Halflife

The average time required for one half of the atoms in a radioactive sample to decay.

halflife = ln 2 / decay constant


 Natural Abundance

The percentage of a particular isotope in the naturally occurring element.


 Decay

The diminution of a radioactive isotope due to nuclear emission of alpha particles, beta particles, gamma rays, or positrons, or by electron capture, isomeric transition, or spontaneous fission.

The decay times are given as

µs	microseconds

ms	milliseconds

s	seconds

m	minutes

h	hours

d	days

y	years


 Isotope

One of several nuclides having the same number of protons in their nuclei, but differing in their numbers of neutrons or in energy content.


 Alpha Particle

A nuclear decay product consisting of two protons and two neutrons.  Identical to the nucleus of a Helium-4 atom.


 Beta Particle

An electron emitted during nuclear decay.  Results from the change of a neutron to a proton+electron within the atomic nucleus.


 Gamma Ray

A high-energy photon emitted during nuclear decay.


 Positron

A particle emitted during nuclear decay, which has the mass of an electron, but a positive charge.  Results from the change of a proton to a neutron+positron within the atomic nucleus.


 Spontaneous Fission

A mode of nuclear decay whereby the atomic nucleus splits into two or more relatively large nuclei.  Neutrons and gamma rays usually accompany spontaneous fission.


 Electron Capture

A mode of nuclear decay whereby an orbital electron is absorbed by the nucleus, combining with a proton to form a neutron.


 Isomeric Transition

Many isotopes have more than one geometrical configuration with differing energies.  Isomeric Transition refers to the conversion from one configuration to the other.


 Ionization Potential

The work required to remove a given electron from its orbit and place it at rest at an infinite distance.


 Electron Configuration

The distribution of electrons in orbitals, or shells around the nucleus.  The configuration of the outermost shell of electrons heavily influences the chemical properties of the element.


 Electronegativity

A measure of the electron affinity of an atom.  The difference in electronegativity of two elements forming a compound indicates the tendency toward ionic as opposed to covalent bonding character.


 Neutron Cross Section

A measure of the probability of collision between the nucleus and a slow-moving neutron.


 Atomic Radius

The effective size of a free atom.


 Covalent Radius

The effective size of an atom when covalently bonded.


 Ionic Radius

The effective size of a charged atom in an ionic compound.  The relative sizes of ionic radii in an ionic compound determines the compound's crystal structure.


 Crystal Structure

The arrangement of atoms of the pure element when in the solid state.


 Year of Discovery

The year when the element was first observed.  This may be different from the time when the element was first isolated.


 Discoverer

The person credited with the discovery of the element.


 Origin of Name

The etymology of the element name.


 Abundance, Earth Crust

Proportion of element in the outer lithosphere.  This includes most of the solid shell of rock, but does not include the atmosphere or ocean.


 Abundance, Chondrites

Proportion of element in carbonaceous chondrite I meteorites.  This concentration is widely considered to be representative of the solar system at the time of its formation.


 Abundance, Cosmic

Proportion of element in the visible universe.  Obtained from astronomical spectra.


 Approximate Cost

A very rough measure of the scarcity of the pure element.


 Principal Sources

Naturally occurring minerals or compounds containing the element.  For synthetic elements, the method of synthesis is given.


 Principal Uses

Major modern industries which use the element.


 Properties

Gross physical properties such as appearance, ductility, etc.


 Toxicity

A rough indicator of the element's harmful potential.