The Nucleus (concept)

The nucleus is a central part of an atom, often referred to as the "heart" of the atom. It is extremely small but contains most of the atom's mass. The nucleus is made up of protons, which have a positive charge, and neutrons, which have no charge. Together, these particles are held tightly together by a strong force. The nucleus determines the element's identity (for example, carbon, oxygen) based on the number of protons it contains. It is surrounded by electrons, which orbit around the nucleus and play a crucial role in chemical reactions and bonding.