Chemistry vocab
Group-a number of people or things that are located close together or are considered or classed together.
Periods- a length or portion of time.
Element- a part or aspect of something abstract, especially one that is essential or characteristic.
Compound- a thing that is composed of two or more separate elements; a mixture.
Atomic number-the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
Atomic mass-the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
Atom- the basic unit of a chemical element.
Ion-an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Valence electron-In chemistry, a valence electron is an electron that is associated with an atom, and that can participate in the formation of a chemical bond; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
Metal-a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g., iron, gold, silver, copper, and aluminum, and alloys such as brass and steel)
Nonmetal-an element or substance that is not a metal.
Metalloid-an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. They are electrical semiconductors
Noble gas-any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (18) of the periodic table. They were long believed to be totally unreactive but compounds of xenon, krypton, and radon are now known.
Alkali metal- any of the elements lithium, sodium, potassium, rubidium, cesium, and francium, occupying Group IA (1) of the periodic table. They are very reactive, electropositive, monovalent metals forming strongly alkaline hydroxides.
Alkaline earth metal-any of the elements beryllium, magnesium, calcium, strontium, barium, and radium, occupying Group IIA (2) of the periodic table. They are reactive, electropositive, divalent metals, and form basic oxides that react with water to form comparatively insoluble hydroxides.
Halogen-any of the elements fluorine, chlorine, bromine, iodine, and astatine, occupying group VIIA (17) of the periodic table. They are reactive nonmetallic elements that form strongly acidic compounds with hydrogen, from which simple salts can be made.
Cation-a positively charged ion, i.e., one that would be attracted to the cathode in electrolysis.
Anion-a negatively charged ion, i.e., one that would be attracted to the anode in electrolysis.
Electron affinity-Electron affinity is defined as the change in energy (in kJ/mole) of a neutral atom (in the gaseous phase) when an electron is added to the atom to form a negative ion.
Electronegativity-Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used. Fluorine (the most electronegative element) is assigned a value of 4.0, and values range down to caesium and francium which are the least electronegative at 0.7.
Ionization energy-The ionization energy is the exact quantity of energy that it takes to remove the outermost electron from the atom.
Atomic radii- a measure of the size of its atoms. Usually distance from nucleus to the boundary of surrounding cloud electrons
Density-the degree of compactness of a substance
Melting point-the temperature at which given solid will melt
Reactivity-the state or power of being reactive or the degree to which a thing is reactive
The extent to which a nuclear reactor deviates from a steady state
Periods- a length or portion of time.
Element- a part or aspect of something abstract, especially one that is essential or characteristic.
Compound- a thing that is composed of two or more separate elements; a mixture.
Atomic number-the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
Atomic mass-the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
Atom- the basic unit of a chemical element.
Ion-an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
Valence electron-In chemistry, a valence electron is an electron that is associated with an atom, and that can participate in the formation of a chemical bond; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
Metal-a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g., iron, gold, silver, copper, and aluminum, and alloys such as brass and steel)
Nonmetal-an element or substance that is not a metal.
Metalloid-an element (e.g., germanium or silicon) whose properties are intermediate between those of metals and solid nonmetals. They are electrical semiconductors
Noble gas-any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (18) of the periodic table. They were long believed to be totally unreactive but compounds of xenon, krypton, and radon are now known.
Alkali metal- any of the elements lithium, sodium, potassium, rubidium, cesium, and francium, occupying Group IA (1) of the periodic table. They are very reactive, electropositive, monovalent metals forming strongly alkaline hydroxides.
Alkaline earth metal-any of the elements beryllium, magnesium, calcium, strontium, barium, and radium, occupying Group IIA (2) of the periodic table. They are reactive, electropositive, divalent metals, and form basic oxides that react with water to form comparatively insoluble hydroxides.
Halogen-any of the elements fluorine, chlorine, bromine, iodine, and astatine, occupying group VIIA (17) of the periodic table. They are reactive nonmetallic elements that form strongly acidic compounds with hydrogen, from which simple salts can be made.
Cation-a positively charged ion, i.e., one that would be attracted to the cathode in electrolysis.
Anion-a negatively charged ion, i.e., one that would be attracted to the anode in electrolysis.
Electron affinity-Electron affinity is defined as the change in energy (in kJ/mole) of a neutral atom (in the gaseous phase) when an electron is added to the atom to form a negative ion.
Electronegativity-Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used. Fluorine (the most electronegative element) is assigned a value of 4.0, and values range down to caesium and francium which are the least electronegative at 0.7.
Ionization energy-The ionization energy is the exact quantity of energy that it takes to remove the outermost electron from the atom.
Atomic radii- a measure of the size of its atoms. Usually distance from nucleus to the boundary of surrounding cloud electrons
Density-the degree of compactness of a substance
Melting point-the temperature at which given solid will melt
Reactivity-the state or power of being reactive or the degree to which a thing is reactive
The extent to which a nuclear reactor deviates from a steady state