In the periodic table, what is the trend for atomic radius as you move from left to right across a period (horizontal row)?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. Atomic radius decreases.
As you move from left to right across a period in the periodic table, the atomic radius decreases. This trend occurs because, with each successive element, one proton and one electron are added. While the electron goes into the same energy level, the increasing positive charge in the nucleus pulls the electron cloud closer due to stronger electrostatic attraction. This results in a smaller atomic radius. Even though electrons are added, they do not increase the shielding effect significantly within the same shell.