Science
The basic particle from which all elements are made; the smallest particle of an element that has
the properties of that element.
Atom
A tiny particle that moves around the outside of the nucleus of an atom whose weight is next
to nothing compared to the weight of a proton or a neutron.
Electron
A small particle in the nucleus of the atom, with no electrical charge.
Neutron
The number of protons in the nucleus of an atom.
Atomic Number
A substance made of two or more elements chemically combined in a specific ratio, or
proportions.
Compound
The way a mineral reflects light from its surface.
Luster
A substance that can conduct electric current under some conditions.
Semiconductors
A term used to describe a material that can be pulled out into a long wire.
Ductile
Elements in the same vertical column of the periodic table; also called a family. Groups, or
elements in the same column, have more in common than elements in the same period, or row.
Group
A one or two-letter abbreviation for an element.
Chemical Symbol
The sum of protons and neutrons in the nucleus of an atom.
Mass Number
A small, positively charged particle that is found in the nucleus of an atom.
Proton
The way in which acids react with some metals so as to wear away the metal.
Corrosive
A compound that changes color in the presence of an acid or a base.
Indictator
A substance that tastes bitter, feels slippery, and turns red litmus paper blue.
Base
An ionic compound made from the neutralization of an acid with a base.
Salt
A reaction of an acid with a base, yielding a solution that is not as acidic or basic as the
starting solutions were.
Neutralization
An ion that is made of more than one atom.
Polyatomic ion
A term used to describe material that can be hammered or rolled into flat sheets.
Malleable
The ease and speed with which an element combines, or reacts, with other elements and
compounds.
Reactivity
A horizontal row of elements in the periodic table.
Period
The electrons that are in the highest energy level of an atom and that are involved in
chemical bonding. The maximum number of valance electrons is 8.
Valance Electron
An atom with the same number of protons and a different number of neutrons from other
atoms of the same element. Examples of isotopes would have the same element. Carbon-12 and
carbon-14 are isotopes. The number refers to the mass number. The name of the element deals with
the number of protons.
Isotope
The central core of an atom which contains protons and neutrons.
Nucleus
A covalent bond in which electrons are shared unequally.
Polar Bond