With reference to the radioactivity, which of the following statements is/are correct?1.Radioactivity is a nuclear property.2.Hydrogen bomb is prepared on the principle of nuclear fission.Select the correct answer using the codes given below. Codes:

1. A

   Only 1

   Statement 1 is correct: radioactivity is a nuclear property—decay depends on the unstable nucleus, not on chemical bonding or temperature in ordinary conditions. Statement 2 is false: a hydrogen bomb is built on thermonuclear fusion (usually triggered by a fission primary), not on fission as the operating principle. Therefore only 1 is the official key.

2. B

   Only 2

   Only 2 would treat the hydrogen bomb as a fission device. That description belongs to the atom bomb (uranium/plutonium fission), not to the H-bomb.

3. C

   Both 1 and 2

   Both 1 and 2 cannot stand because the fusion-versus-fission error in statement 2 remains. A true nuclear-property line plus a false bomb line is not ‘both’.

4. D

   Neither 1 nor 2

   Neither 1 nor 2 would discard the correct claim that radioactivity is nuclear. The item is not a double negative.

Summary. Official key is (a) only 1. Radioactivity is spontaneous nuclear decay (alpha, beta, gamma). Fission weapons split heavy nuclei; fusion weapons combine light nuclei under extreme heat. Examiners routinely swap fission and fusion on bomb items. Honour the stored letter (a).