Question

Identify the symbol for the missing element in each period.

Te

I

Xe

Answer 1

Step 1: Find the period number.

• The number of shells = period number.
• According to the question, all the elements represented belong to the same period.

Step 2: Finding the period number for one element.

Tellurium $\left(\mathrm{Te}\right)$:

• The atomic number is $52$.
• Electrons per shell $=2,8,8,18,16$.
• Number of shells $=5$.
• So, the elements belong to the period $5$.
• The elements belonging to period $5$ from the p-block series are Indium $\left(\mathrm{In}\right)$, Tin $\left(\mathrm{Sn}\right)$, Antimony $\left(\mathrm{Sb}\right)$, Tellurium $\left(\mathrm{Te}\right)$, Iodine $\left(\mathrm{I}\right)$, and Xenon $\left(\mathrm{Xe}\right)$.

Hence, the missing element is Antimony $\left(\mathrm{Sb}\right)$.