Q.Write any three properties of neutrons.

The neutron is a chargeless nuclear particle, slightly heavier than the proton, that is stable inside a nucleus but decays with a half-life of about 12 minutes when free.

Discovery

The neutron was discovered by James Chadwick in 1932, by bombarding beryllium with alpha particles and observing a highly penetrating, electrically neutral radiation. It is, along with the proton, one of the two nucleons that make up atomic nuclei.

Properties

1. No electric charge: The neutron is electrically neutral. Consequently it is not deflected by electric or magnetic fields, and it can penetrate matter (including nuclei) more easily than a charged particle of similar energy, since it does not experience Coulomb repulsion from the positively charged nucleus.

2. Mass: The rest mass of a neutron is $m_n=1.6749\times10^{-27}\,kg$, slightly greater than the mass of a proton ($m_p=1.6726\times10^{-27}\,kg$).

3. Instability outside the nucleus: While bound inside a stable nucleus a neutron does not decay, but a free neutron is unstable, undergoing beta decay with a half-life of about 12 minutes (more precisely about 10.2 minutes/614 s in modern measurements, commonly quoted as $\sim$12–13 minutes in textbooks): …