List-I shows different radioactive decay processes and List-II provides possible emitted particles. Match each entry in List-I with an appropriate entry from List-II, and choose the correct option.
| List-I | List-II |
|---|---|
| (P) | (1) |
| (Q) | (2) |
| (R) | (3) |
| (S) | (4) |
| (5) |
Correct Answer :
P → 4, Q → 3, R → 2, S → 1
Solution :
The correct option is P → 4, Q → 3, R → 2, S → 1.
To determine the emitted particles in each radioactive decay process, we apply the conservation of mass number (A) and atomic number (Z):
1. Emitting an
particle
decreases the mass number by 4 and the atomic number by 2.
2. Emitting a
particle
leaves the mass number unchanged and increases the atomic number by 1.
3. Emitting a
particle
leaves the mass number unchanged and decreases the atomic number by 1.
Let us analyze each process step-by-step:
(P)
Change in mass number (A): 238 - 234 = 4.
This indicates the emission of 1
particle (which reduces A by 4 and Z by 2).
After emitting 1
particle, the atomic number becomes: 92 - 2 = 90.
The final product has an atomic number of 91, which requires an increase of 1 in Z.
This increase is achieved by emitting 1
particle.
Hence, process (P) emits one
particle and one
particle.
Thus, P → 4.
(Q)
Change in mass number (A): 214 - 210 = 4.
This corresponds to the emission of 1
particle.
After emitting 1
particle, the atomic number becomes: 82 - 2 = 80.
The final product has an atomic number of 82, requiring an increase of 2 in Z.
This increase is achieved by emitting 2
particles.
Hence, process (Q) emits two
particles and one
particle.
Thus, Q → 3.
(R)
Change in mass number (A): 210 - 206 = 4.
This corresponds to the emission of 1
particle.
After emitting 1
particle, the atomic number becomes: 81 - 2 = 79.
The final product has an atomic number of 82, requiring an increase of 3 in Z.
This increase is achieved by emitting 3
particles.
Hence, process (R) emits three
particles and one
particle.
Thus, R → 2.
(S)
Change in mass number (A): 228 - 224 = 4.
This corresponds to the emission of 1
particle.
After emitting 1
particle, the atomic number becomes: 91 - 2 = 89.
The final product has an atomic number of 88, requiring a decrease of 1 in Z.
This decrease is achieved by emitting 1
particle.
Hence, process (S) emits one
particle and one
particle.
Thus, S → 1.
Combining all the matches gives:
P → 4, Q → 3, R → 2, S → 1
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