Question

The study of radioactive decay results in the emission of particles, leading to four observations: (A) No change in atomic and mass number, (B) Atomic number decreases by 1, (C) Study of radioactive decay of unstable nuclei resulting in emission of a
particle leads us to four different observations listed below:
(A) Nochange in atomic number and mass number.
(B) Nochange in mass number but the atomic number decreases by 1.
(C) Nochange in mass number but the atomic number increases by 1.
(D) Atomic number decreases by 2 and the mass number decreases by 4.
Arrange the particles emitted in the above four cases in correct sequence:

• A. Alpha particle, positron, electron, photon
• B. Alpha particle, electron, positron, photon
• C. Photon, positron, electron, alpha particle
• D. Alpha particle, positron, photon, electron

Answer 1

The Correct Option is C

Given Observations:

Observation	Atomic Number Change	Mass Number Change	Particle Emitted
A	No change	No change	Photon (γ)
B	Decreases by 1	No change	Positron (β⁺) or Electron Capture
C	Increases by 1	No change	Electron (β⁻)
D	Decreases by 2	Decreases by 4	Alpha particle (α)

Correct Sequence:

From the table, the particles correspond to:

γ (A), β⁺ (B), β⁻ (C), α (D)

Answer: The correct sequence is \(\boxed{\text{photon, positron, electron, alpha particle}}\) (Option 3)

Answer 2

- Case A: No change in atomic and mass numbers, which corresponds to photon emission.
- Case B: A decrease in atomic number by 1 corresponds to positron emission.
- Case C: An increase in atomic number by 1 corresponds to electron (beta) emission.
- Case D: A decrease in atomic number by 2 and mass number by 4 corresponds to alpha particle emission