Question

what happens to the atomic radius as you move across a period from left to right?
it increases
it stays the same
it decreases

Explanation:

In the periodic table, as we move from left to right across a period, the number of protons in the nucleus increases, which increases the positive charge of the nucleus. This increased nuclear charge pulls the electrons in the outermost shell more strongly towards the nucleus. Although the number of electron shells remains the same across a period, the effective nuclear charge experienced by the outermost electrons increases, leading to a decrease in the atomic radius.

Answer:

The option "It decreases" (the third option with the label "It decreases") is correct.