2 Chemical Bond: a link that atoms or electrically charged particles can form with each other.
3 Chemical Formula: a way of using letters and numbers to show how much of each element is in a substance.
4 Ion: an electrically charged particle with unequal numbers of protons and electrons.
5 Molecule: a group of bonded atoms that acts like a single.
6 Chemical Property: a way of describing how a substance changes chemically with other substances.
7 Exothermic: a reaction that gives off heat.
8 Endothermic: a reaction that absorbs heat.
