Atomic Nuclei

All matter around us is made from atoms. A glass of water, a rock and your body are all made from atoms. These atoms are incredibly small—and the particles making them up are even smaller. Most of an atom is actually empty space.

The nucleus is a small, dense lump at the centre of an atom containing particles known as nucleons. These are the heavy particles of an atom—the positively charged protons and the uncharged neutrons.

The positively charged protons in the nucleus experience an electric force pushing them apart. Scientists were puzzled to explain how the nucleus was held together until they discovered another force—the strong nuclear force. This force is able to overcome the electric force and hold the nucleus together.