The total number of isotopes of hydrogen and number of radioactive isotopes among them, respectively are
- (A)3 and 1✓ Correct
- (B)3 and 2
- (C)2 and 1
- (D)2 and 0
Answer: (A)
Solution
Hydrogen comes in three isotopes: protium with no neutron, deuterium with one, and tritium with two, so the count of isotopes is three. Of these only tritium is unstable, undergoing beta decay, while protium and deuterium are stable. So there are three isotopes in all and just one of them is radioactive.
JEE Main · 2019 · 10 Jan 2019 · Shift 1 · Single correct option