UPSC Prelims PYQ | Atomic Structure
Q1. Isotopes of the same element differ in the number of (a) Protons (b) Neutrons (c) Electrons (d) Positrons (UPSC Prelims 1980) Answer: (b) Neutrons Explanation: Isotopes have the same number of protons but differ in the number of neutrons, resulting in different atomic masses but similar chemical properties. Q2. Mesons are found in (a) …