Periodic Help on Each Element
Chemical Symbols are abbreviations of one to three letters assigned to
chemical elements. An element is one of a group of fundamental substances
that cannot be broken down into simpler substances. The symbols used to
represent the chemical elements are mostly abbreviations of their common names.
The Atomic Number indicates the number of protons, or positively charged
mass units in the nucleus of an atom, upon which its structure and properties
depand. The atomic number also represents the location of an element in the
Periodic Table. It is always the same as the number of negatively charged
electrons in the shells and outside the nucleus of an electrically neutral
atom. Thus an atom is electrically neutral, except in an ionized state, that
is, when one or more electrons have been gained or lost. Atomic numbers range
from 1, for Hydrogen to 108 for the most recently discovered element.
First, Second, Third Ionization Potential
Ionization is the gain or loss of an electron to create an ion. Ionization
Potential is the energy required to remove an electron from a gaseous atom or
ion. It is measured by photoelectron spectroscopy. The units of this quantity
are in electronvolts.
An element group is defined as the number of elements having similar electronic
structure and chemical properties as classified according to the Periodic Table.
There are nine major groups, seven of which are divided into two subgroups,
designated A for the major group elements and B for transition elements. The
two groups that are not so divided are the VIII (transition elements only) and
the noble gas group (sometimes called Group 0).
Crystal Structure graphically displays the crystal structure of the selected
element. These structures can include; hex, cubic, cubic body, cubic face,
rhombo, mono, ortho, and tetra.
The Atomic Weight of an element is the average weight (or mass) of the naturally
occuring mixture of isotopes of the element relative to an arbitrarily assigned
mass of 12.0000 for carbon-12. The true atomic weight of carbon, when masses of
its isotopes are averaged is 12.01115. The total mass of any atom is the sum of
the masses of all its constituents (protons, neutrons, and electrons). The atomic
weight of an element expressed in grams is called the gram atomic weight. It's
UNITS are expressed in Au or Atomic units.
Thermal Conductivity is the property of a substance or mixture of transmitting
heat uniformly troughout its mass, the energy being passed from one atom to another
with little if any loss. Crystalline solids (especially metals and alloys) are good
thermal conductors because of their high density. Liquids (water) and polymers
(rubber) usually are not. The units for thermal conductivity are W/cm.
The melting point of an element is defined as the temperature at which the forces
which unite the crystals of a solid are ruptured, resulting in a change from the
crystalline to the amorphous state. This change involves adsorption of a
characteristic amount of heat for each solid substance, called the heat of fusion.
Synonymous with the term Melting Point is freezing point, where the change is from
amorphous to crystalline, the only difference being that heat is removed from
instead of absorbed by the substance are indentical. An example is for water,
0 degrees celsius. The units for melting point are in Kelvin or K.
Vaporization or Heat Vaporization is defined as the amount of energy (heat) required
to convert a substance from the liquid state to the gaseous state with no temperature
change. It is also called the latent heat of vaporization. It is usually measured
at the normal boiling point of the substance. That is, the temperature at which the
liquid boils at 1 atmosphere pressure. It is usually expressed as the heat required
to convert a definite weight of the substance into a gas. The units of heat of
vaporization are sometimes expressed as kilocalories per gram-formula weight.
They are alternately expressed as KJ/mol.
Electrical Conductivity is the property of a substance of transmitting electric
current by flow of electrons through a dense solid (metal) or by movement of the
ions of a dissolved electrolyte to the electrodes when a potential difference
exists between them. In the case of solids, no chemical change occurs when the
current is passed, but in electrolyte solutions, decomposition of the electrolyte
solutions, decomposition of the electrolyte takes place. The units for electrical
conductivity are in terms of 1.0e+6/~cm
For an unenclosed liquid or mixture of solids, the Boiling Point is the temperature
at which the upward pressure of molecules escaping from the surface (vapor pressure)
equals the downward pressure of the atmosphere (14.7 pounds per square inch at sea
level). When the liquid is in a closed container, the boiling point may be defined
as the equilibrium, that is, when evaporation and condensation are occuring at the
same rate at constant atmospheric pressure. The temperature is the same in both
cases. In summary, the boiling point of anelement is the temperature at which the
vapor pressure of a liquid is at 1 ATM. The units for Boiling Point are in Kelvin
Heat of Fusion
Heat of Fusion is defined as the amount of energy (heat) required to convert a
substance from the solid state to the liquid state with no temperature change,
it is also called the latent heat of fusion; usually measured at the melting point
of the substance. That is, the temperature at which the solid and liquid forms are
in equilibrium, and usually expressed as the heat required to convert a definite
weight of the substance into a liquid. Its units of Heat of Fusion are expressed
Ionic Radius is the radius of an ion (an atom or group of atoms that gained or lost
electrons and therefor carries a charge).
Atomic Volume is the volume occupied by one mole of atoms of an element. The units
for atomic volume are cm3/mol, where mol represents 1 mole.
The Specific Heat is the quanity of heat, or heat capacity that is required to raise
the temperature of one gram of substance by one Kelvin either at constant volume or
constant pressure. Specific Heat is used in the calculation of enthalpy changes at
different tamperatures and entropy changes. The units of specific heat are expressed
The Atomic Radius is defined as half the distance of closest approach of atoms in the
structure of the element, that is, from the nucleus to the outer shell electron(s).
Atomic radius is easily defined for regular structures, like close-packed metals,
but is not easily defined for elements with irregular structures. For example As.
Also refer to Covalent Radius. The units of atomic radius are expressed in angstroms
Density is defined as the ratio of weight (mass) to volume of any substance, usually
expressed as grams per cubic centimeter. If 1 cc of a substance weights 2 grams per
cc. Density is closely related to specific gravity, which is the ratio of the weight
(or mass) to the weight of the same volume of a standard substance usually water.
Since 1 cc of water weights almost exactly 1 gram, water is taken as the reference
material for liquids and solids, air is used for gasses. Units for density are in
terms of grams per cm cubbed or gm/cm3.
Please note: The following 11 elements are in a gaseous state and are measured at 273
Kelvin and 1 ATM: Hydrogen, Helium, Nitrogen, Oxygen, Flourine, Neon, Chlorine,
Argon, Krypton, Xenon, Radon.
The Covalent Radius, also known as bond lenght, is the internuclear distance atoms
in a molecule. Covalent bond lenghts may be assigned to pairs of atoms with similar
bonds. That is, it is one half the distance between the centers of two atoms that
are bonded together covalently. Coalent radius is measured by X-Ray Diffraction in
solids by determination of properties such as compressibility and entropy in the gas
and liquid phases. The units of Covalent Radius are expressed in angstroms or Â.
Oxidation States is the formal number of electrons associated with an element in a
compound on a scale in which the oxidation state of a non-combined element (or
non-compound) is zero. The Oxidation State of would be required to create an inert
gas electron configuration. There are no nits for Oxidation State.
State is the form of which an element takes, it can be solid, liquid, or gas.
The Electron Configuration is an arrangement of atoms and molecules. The number of
electrons in an atom is the same as the atomic number, ranging from 1 for Hydrogen
to 103 for Lawrencium. These are arranged in one to seven elements to form complete
outer shells accounts for the valence of the element, these valence electrons play
an essential role in chemical bonding. In Quick Chemist, the electron configuration
or SPDF Notation is a method of describing the electron configuration of an atom in
which the number of electrons assigned to each orbit are denoted by superscript
numerals. For example, the Electron Configuration of Chlorine in SPDF Notation is
1s22s22p63s23p5. I have further provided an underscore to seperate each shell, so
it is displayed like 1s2_2s2_2p6_3s2_3p5.
Electronegativity is the extent to which an atom can attract electrons from outside
itself and thus become negatively charged, this tendency is due to the attractive
force exerted by the nuclei of atoms having vacanies in their outer shells. This
attraction makes possible the formation of both covalent and ionic bonds and is thus
a fundamental factor in the formation of chemical componds.
The Color SPECTRAL displays a spectrograph showing spectral lines in proportion to
that elements color spectrum; from ultraviolet, violet, indigo, blue, green, yellow,
orange, red, to infrared. The ultraviolet and infrared regions are displayed in
white. The scale along the color bar is proportional to the maximum and minimum
wavelenghts display. Along with the spectrograph, there is a windows that pops up
and displays the selected spectral lines angstroms along with their halflives.
The Isotopes will display the radioactive isotopes that are characteristic of the
active paged element. This display's the radioactive isotopes and their
The Elecronic Configuration displays the configuration of an elements electrons
about its nucleous. SPDF orbital equations are given.
Crystal Structure displays the crystal structure of the selected element. These
structures can include: Hex, Cubic, Cubic Body, Cubic Face, Rhombo, Mono, Ortho,
By Milt Hull , HullSoft Enterprises
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