Atoms & structure
Neutron — নিউট্রন
Quick answer
A neutron is the uncharged particle in the nucleus; it adds mass but no charge.
Definition
A neutron is a particle in the nucleus with no electric charge and a mass almost equal to a proton's — about 1 u. Being neutral, it adds weight without adding repulsion, and its presence helps bind the positively charged protons together so the nucleus stays stable. Atoms of one element that differ only in neutron number are isotopes. Loose on its own, a neutron is unstable and decays within minutes; packed inside a nucleus, it can last forever.
For example
Carbon-12 carries 6 protons and 6 neutrons; carbon-14 has the same 6 protons but 8 neutrons — same element, heavier nucleus.