Two important properties of these subatomic particles that we need to consider are their electrical charges and their weight. Both protons and electrons carry minute electrical charges. The charge on the proton is positive, whereas the charge on the electron is negative. As opposite charges attract, it is partly the positive charge of the protons that keeps the electrons in “orbit” around the nucleus. Neutrons carry no charge.
With regards to weight, electrons can be considered weightless, but both protons and neutrons contribute a tiny, but significant weight to the atom.
Although all atoms conform to this basic arrangement, they differ from one another in their composition, depending on the number of protons, neutrons and electrons they contain. In fact there are nearly 100 different types of atoms known to occur naturally, the diversity of the materials around us being made up by the many ways that these relatively few types of atoms can react together.