How does atomic radius change from left to right across a period in the periodic table?

a. it first decreases, then increases.
b. it tends to decrease.
c. it first increases, then decreases.
d. it tends to increase.

Option (b) is the correct answer.

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 are added 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.

Thus, we can conclude that atomic radius tends to decrease from left to right across a period in the periodic table.