Additional Science Chemistry

Atoms - protons, neutrons, electrons.

Elements = 1 atom.

Compounds = 2+ elements joined by a chemical reaction.

                      = covalent bonding - 2 atoms share 2 electrons.

                      = ionic bonding - become charged ions by + or - electrons.

Periods - (rows), Groups - (columns).

Ion = charged atom.

ion = positively charged _ atom - 1+ electron.

ion = negatively charged _ atom + 1+ electron.