Question

Decrease in atomic number is observed during:

• A. Alpha emission
• B. Beta emission
• C. Positron emission
• D. Electron capture

Answer 1

Answer: (A), (C), (D)

Electron capture

$\mathrm{Alpha}\mathrm{emission}:AZX\to A-4Z-2Y+42\mathrm{He}$
$\mathrm{Positron}\mathrm{emission}:AZX\to AZ-1Y+01e$

$\mathrm{Electron}\mathrm{capture}:AZX+0-1e\to AZ-1Y$

$\mathrm{Beta}\mathrm{emission}:AZX\to 0-1\beta +AZ+1Y$

Hence, decrease in atomic number is observed in alpha emission, positron emission and electron capture, whereas increase in atomic number is seen during $\beta$ emission.