Proton(+), Neutron(0), Electron(-)
A proton is in the nucleus, is heavy, and is positivly charged. An electron flies around the nucleus, is light, and negativly charged.
Different number of protons
Different mass numbers because it has a different number of nutrons
Nutrons and protons are in the nucleus. However, a nutron has no charge and a proton has a positive (+) charge.
The electrons and protons cancel eachother out. For example, a heluim atom has 2 nutrons. This means it also has 2 electrons. These cancel eachother out.
Oxygen-17 has 1 more nutron than Oxygen-16
Protons and electrons have a charge, but nutrons don't.
Because 10-12=-2, and you can't have negative nutrons.