Atomic Nucleus

Atomic nuclei are collections of positively charged protons and (as the name suggests) neutrally charged neutrons, which are held together by a fundamental force known as the strong force. Although the nucleus typically makes up just .01% of an atom’s volume, more than 99.9% of the atom’s mass is harbored there. An understanding of the nucleus is important for understanding how an atom will react with its surrounding environment, as the chemical properties of a substance are determined by the negatively charged electrons enshrouding the nucleus. The number of protons in the nucleus is usually equal to the number of electrons, and a mismatch results in the creation of an ion.