Neutron
Definition
The neutral particle in the nucleus. It adds mass and helps hold the nucleus together, but it does not change which element the atom is.
Symbol: ·
Technical definition
A neutron is an electrically neutral subatomic particle (mass about 1.0087 u) in the atomic nucleus. Together with protons it accounts for nearly all atomic mass, and varying neutron counts produce isotopes of the same element.
Example
Carbon-12 has 6 neutrons and carbon-14 has 8 neutrons. Both are carbon, but carbon-14 is radioactive.
Common confusion
Neutrons barely affect chemical behavior. Isotopes of an element react almost identically because chemistry is driven by electrons, not neutrons.