Basic unit of matter

A molecule composed of one kind of atom; cannot be broken into simpler units by chemical reactions.

Groups of two or more atoms held together by chemical bonds

the process by which one or more substances change to produce one or more different substances

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

A subatomic particle that has a positive charge and that is found in the nucleus of an atom

Atoms of the same element that have different numbers of neutrons

regions around the nucleus in which given electron or electron pair is likely to be found

movement of electrons from one element to another; important in creation of ionic bonds

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

A subatomic particle that has no charge and that is found in the nucleus of an atom

An isotope that has an unstable nucleus and undergoes radioactive decay

atoms react by gaining or losing electrons so as to acquire the stable electron structure of a noble gas, usually eight valence electrons

Formed when one or more electrons are transferred from one atom to another

Attraction between a slightly positive hydrogen atom and a slightly negative atom.

A subatomic particle that has a negative charge

the ability to combine and to chemically bond with each other

The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom.

the process in which an electric current is used to produce a chemical reaction, such as the decomposition of water

Having an affinity for water.

center of the atom that contains protons and neutrons

uses the half life of carbon 14 to determine the age of organic matter

"Group 18" the group has not been added to the periodic table yet; the Group of elements having exceptional high ionization energies (Helium)

attraction of an atom for an electron in a bond (when covalent bond is already formed)

the amount of energy needed to change the temp of 1kg of the substance by 1oC