1
number of neutrons + number of protons
2
area where electrons are likely to be found
3
number of protons in an atom
4
subatomic particle with a negative charge
5
center of an atom which contains most of the mass of the atom
6
atoms with the same number of protons but different numbers of neutrons
7
subatomic particle found in the nucleus that has no charge
8
subatomic particle found in the nucleus that has a positive charge
9
smallest piece of a substance that still has the properties o f that substance
