Question

In a group, if the atomic radius of the second element is 152 pm. What is the atomic radius of the third element - more than or less than 152 pm?

Answer 1

The vertical columns present in the periodic table are called periods.

In the periodic table total of 18 groups are present.

• In a group moving from top to bottom, the number of valence electrons remains the same but the number of valence shells gets increased by one.
• The force of attraction is inversely proportional to the square of the effective distance between nucleus and electron.
• With the increase in shell, the effective force of attraction decreases because the effective distance between the nucleus and outermost shell increases.
• The atomic radius of the element increases in a group moving from top to bottom in the periodic table.
• With the decrease of the nuclear force of attraction, the atomic size of the element keeps on increasing.

Therefore, in a group, if the atomic radius of the second element is $152\mathrm{pm}$, then the atomic radius of the third element will be more than $152\mathrm{pm}$ .