Question

n the third period of the periodic table, sodium is followed by magnesium, aluminum, silicon, and phosphorus. Which of these elements has the smallest atomic size? sodium magnesium aluminum silicon phosphorus

Answer 1

You need to follow the atomic radius trend, the atomic radius decreases as you go across the period, and the atomic radius increases as you go down a group.
Between Sodium, Magnesium, Aluminum, silicon, and phosphorus, Sodium has the biggest atomic radius.

Answer 2

Answer: Option (5) is the correct answer.

Step-by-step explanation:

When we move from left to right across a period in a periodic table then there will occur a decrease in size of the atoms because electrons add to the same shell.

As a result, nucleus tends to pull the electrons towards itself due to which shrinkage in the size of atoms tends to occur.

Sodium is placed at the extreme left of row 3 and phosphorous is placed at the right side of row 3.

This means atomic size is decreasing from sodium to phosphorous.

Thus, we can conclude that out of the given options phosphorus element has the smallest atomic size.