Question

The periodic table consists of 18 periods. An isotope of copper, on bombardment with protons, undergoes a nuclear reaction yielding element $X$ as shown below. To which group, element $X$ belongs in periodic table:
${}_{29}^{63}Cu{+}_1^{1}H\to 6_0^{1}n+\alpha +2_1^{1}H+X$

• A. $8$
• B. $6$
• C. $10$
• D. $4$

Answer 1

Answer: (A)

Step 1:

${}_{29}^{63}Cu{+}_1^{1}H\to 6_0^{1}n{+}_2^{4}He\left(\alpha \right)+2_1^{1}H{+}_{26}^{52}X$
Atomic number $26$ represents $Fe$ which belongs to group number $8$

Step 2:
Alternative path:
$Z=26$
Electronic configuration: $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^6$
Hnce, the element $X$ belongs to d block.

Step 3:
Group number = electrons in $(n-1)$ subshell + number of electrons in valence shell
$\Rightarrow 6+2=8$