Physics
An atomic nucleus A is composed of 84 protons and 128 neutrons. The nucleus A emits an alpha particle and is transformed into a nucleus B.
(i) What is the composition of B?
(ii) The nucleus B emits a beta particle and is transformed into a nucleus C. What is the composition of C?
(iii) What is mass number of the nucleus A?
(iv) Does the composition of C change if it emits gamma radiations?
Answer
(i) After the emission of an alpha particle from A, the resulting nucleus B has 2 protons and 2 neutrons less than the part nucleus (i.e., A), therefore, the nucleus B has :
No. of proton = 82
No of neutron = 126
(ii) After the emission of a beta particle from B, the resulting nucleus C 1 proton more and 1 neutron less than the part nucleus (i.e., B) therefore, the nucleus C has :
No. of proton = 83
No. of neutron = 125
(iii) Mass number of the nucleus A = (84 + 128 ) = 212.
(iv) No, the composition of a nucleus does not change if it emits gamma radiation.
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