Chemical Changes

Compound: a chemical combination of two or more elements.


Chemical bond: a link that atoms or electrically charged particles can form with each other.


Chemical formula: a way of using letters and numbers to show much of each element is in a substance.


Ion: an electrically charged particle with unequal numbers of protons and electrons.

Molecule: a group of bonded atoms that acts like a single particle.

Chemical propety: a way of describing how a substance changes chemically with other substances.


Exothermic: a reaction that give off heat.

Endothermic: a reaction that absorbs heat.