A neutron is an electrically neutral subatomic particle located in the nucleus. Because it carries no charge, the number of neutrons does not affect the element's identity, but it does affect the atom's mass and the stability of the nucleus. Atoms of the same element with different numbers of neutrons are called isotopes.

中子是位于原子核中、不带电荷的亚原子粒子。由于不带电,中子的数目不影响元素的种类,但会影响原子的质量和原子核的稳定性。同种元素中子数不同的原子称为同位素。