Question

An element 'X' with Z = 112 has been recently discovered. To which group and period will it belong?

• A. 11, 5
• B. 12, 7
• C. 7, 12
• D. 5, 11

Answer 1

The correct option is B 12, 7

The electronic configuration of element X is
$[Rn{]}^{86}$ $5f^{14}$ $6d^{10}$$7s^2$. It belongs to d - block as last electron enters in the d subshell. As number of electrons in (n-1) d subshell and valence shell is equal to 12 i.e. 10 + 2 = 12. So, it belongs to group 12 and to period 7 of the periodic table as principal quantum number of valence shell is 7 (i.e., $7s^2.$)