Reactor Heat Production
An atom has a nucleus at its center and one or more electrons moving around it as shown schematically in Fig. 13.1. The nucleus is composed of N number of neutrons which are electrically neutral and Z number of protons which have a positive electric charge. The number of protons Z is called the atomic number, and the sum of the numbers of neutrons and protons A (=N + Z) is called the mass number of the atom.