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A nucleus has a radius of 7.2 * 10⁻¹⁵ m. It undergoes alpha-decay, and the daughter nucleus has a neutron-to-proton ratio of 65/41. Which of the following statements is/are correct? (A) Parent nucleus is 84Po. (B) Daughter nucleus is 82Pb. (C) Mass number of daughter nucleus is 216. (D) Mass number of parent nucleus is 216.

1. Parent nucleus is 84Po.
2. Daughter nucleus is 82Pb.
3. Mass number of daughter nucleus is 216.
4. Mass number of parent nucleus is 216.

Correct answer: Parent nucleus is 84Po.

Solution

Parent: R = R0*A^(1/3) gives A = 216. After alpha decay: daughter A = 212, Z = 82 (Pb-212), parent Z = 84 (Po-216). Options A, B, D are correct; C is incorrect (daughter mass number is 212, not 216).

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