What we know now is that the nucleus is made up of protons and neutrons and contains most of the atom's mass. All atoms of a given element usually have the same number of protons and electrons. The attraction between positively charged protons and negatively charged electrons is what holds the atom together. Sometimes the atoms in an element have have one or more extra electrons, and sometimes they have fewer. This sharing of electrons is one of the forces that binds atoms together to make compounds.
Most atoms also contain neutrons, which have no charge.
Now, if you understand all that, let's leave you with some ideas for future exploration. We know now that even the teensy subatomic particles discussed here aren't the smallest. E-mail us with general site comments or suggestions. Newsticker for your site Earth . The Edge .