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 how 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 property: A way of describing how a substance changes chemically with other substances.

exothermic: A reaction that gives off heat.

Endithermic:

                                  

                          A reaction that absorbs heat.