Element - ANS-A pure substance that cannot be further broken down by the methods of
chemistry
Atom - ANS-The basic unit of matter
Nucleus - ANS-The dense central part of an atom containing protons and neutrons
Proton - ANS-A positively charged particle in the atomic nucleus
Neutron - ANS-An electrically neutral particle in the atomic nucleus
Electron - ANS-A negatively charged particle that moves around the atomic nucleus
Atomic Mass - ANS-The mass of the atom determined by the number of protons and neutrons
Isotopes - ANS-Atoms of the same element that have different numbers of neutrons
Ion - ANS-An electrically charged atom or molecule
Orbital - ANS-A region space where an electron is present most of the time
Shell (electron) - ANS-An energy level
Periodic Table of the Elements - ANS-The arrangement of the chemical elements in tabular
form, organized by their chemical properties
Molecule - ANS-A substance made up of two or more atoms
Chemical Bond - ANS-Any form of attraction between atoms that hold them together
Valence Electrons - ANS-The electrons farthest from the nucleus, which are at the highest
energy level
Molecular Orbital - ANS-A merged orbital traversed by a pair of shared electrons
Covalent Bond - ANS-A chemical bond formed by a shared pair of electrons holding two
different atoms together
Double Bond - ANS-A covalent bond in which covalently joined atoms share two pairs of
electrons