JEE Main2010PhysicsNuclear PhysicsActual
A radioactive nucleus (initial mass number A and atomic number Z) emits 3 -particles and 2 positrons. The ratio of number of neutrons to that of protons in the final nucleus will be
Options
- AA-Z-8 Z-4
- BA-Z-4 Z-8
- CA-Z-12 Z-4
- DA-Z-4 Z-2
Correct answer
B. A-Z-4 Z-8
Step-by-step solution
In positive beta decay a proton is transformed into a neutron and a positron is emitted. p ⁺ n ^0+ e ⁺ no. of neutrons initially was A-Z no. of neutrons after decay (A-Z)-3 2 (due to alpha particles) +2 1 (due to positive beta decay) The no. of proton will reduce by 8 . [as 3 2 (due to alpha particles) +2 (due to positive beta decay)] Hence atomic number reduces by 8 .