Question

${}_{92}^{238}U$ (group III B) emits one $\alpha$ particle. What is the group of new element formed?

• A. III B
• B. IV B
• C. IIA
• D. None of these

Answer 1

The correct option is A III B

Thorium lies in actinoid groups. As per CAS group number its position in periodic table is III B (same for all actinoids).