Question

Based on the figure below what type of radioactive decay would you expectCu to undergo? 160 150 140 BI (n/p - 1.52) 130 120 110 100 a) alpha emission 90 (n/p = 1.40) 80 b) beta emission Number of neutrons, n 70 c) gamma emission 60 1:1 neutron- 50 to proton ratio d) 74Cu is not radioactive 40 30 20 10 Fe (n/p = 1.15) mo (n/p - 1.00) 10 20 30 40 50 60 70 80 90 100 Number of protons, p 0 0 www. O a

Answer 1

Answer : Based on the Figure given as above the type of radioactive decay we would expect ⁷⁴Cu to undergo is shown as follows ;

(b) beta emission

This is due to the fact that, the radioactive nuclei having more number of neutrons (as in ⁷⁴Cu the number of neutrons is 45 and the number of protons is 29) than protons would undergo beta emission as like the nuclei of ⁷⁴Cu would undergo beta emission. And ⁷⁴Cu undergo $\beta$ ^- emission or decay, in which a neutron decays into a proton, an electron, and an antineutrino which results in the decrease of neutron to form more stable nucleus.

Thus, based on the Figure given as above the type of radioactive decay we would expect ⁷⁴Cu to undergo is (b) beta emission.

Note :

(1) A neutron in a nucleus will decay if a more stable nucleus results by $\beta$ ^- emission or decay due to decrease in number of neutrons in neutron - rich nuclei which thus decreases the n : p ratio and increases the stability of the nucleus.