Decrease in atomic number is observed during — Nuclear Chemistry and Radioactivity Chemistry Question

💡 Solution & Explanation

In $\alpha$-decay, the atomic number decreases by 2. In positron decay ($\beta^+$) and electron capture, a proton converts into a neutron, decreasing the atomic number by 1. In standard $\beta$-decay ($\beta^-$), a neutron converts into a proton, increasing the atomic number by 1. Therefore, correct answer is A,C,D.