What is the primary reason that atomic radius decreases as you move from left to right across the periodic table even through the number of electrons is increasing?

As you move across a period the electrons are being added to the same shell. But, protons are being added as well. This makes the nucleus more positively charged and, increasing protons has a greater effect than electrons. So, there is a greater nuclear attraction and, because the electrons are being added to the same shell that shell gets pulled in more. This causes a decrease in atomic radius.

Explanation:

Answer Link

adioabiola adioabiola · Answer 2 · 2021-10-21T16:40:13+02:00

The primary reason that atomic radius decreases as you move from left to right across the periodic table is; Due to the increase in electrostatic attraction between the positively charged nucleus and the negatively charged electrons.

The number of shells in elements located in the same period are equal.

However, with successive increase in the atomic number, the number of electrons and protons increases.

Consequently, the electrostatic attraction between the positively charged nucleus and negatively charged electrons increases and the radius reduces accordingly.