Periodic Table

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Periodic Help on Each Element

Atomic Symbol

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.

Atomic Number

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.

Group

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

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.

Atomic Weight

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

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.

Melting Point

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

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

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

Boiling Point

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 or K.

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 as KJ/mol.

Ionic Radius

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

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.

Specific Heat

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 in J/gK.

Atomic Radius

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 or .

Density

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.

Covalent Radius

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 .

Oxidation States

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

State is the form of which an element takes, it can be solid, liquid, or gas.

Electron Configuration

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

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.

Color Spectrum

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.

Isotopes

The Isotopes will display the radioactive isotopes that are characteristic of the active paged element. This display's the radioactive isotopes and their corresponding halflife.

Elecron Configuration

The Elecronic Configuration displays the configuration of an elements electrons about its nucleous. SPDF orbital equations are given.

Crystal Structure

Crystal Structure displays the crystal structure of the selected element. These structures can include: Hex, Cubic, Cubic Body, Cubic Face, Rhombo, Mono, Ortho, and Tetra.

By Milt Hull , HullSoft Enterprises

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