In the periodic table of elements, on moving from left to right across a period, the atomic radius – (1) decreases (2) increases (3) remains unchanged (4) does not follow a definite pattern
(1) decreases Explanation: The atomic radius is the distance from the atomic nucleus to the outermost stable electron orbital in an atom that is at equilibrium. It tends to decrease across a period from left to right. It usually increases while going down a group due to the addition of a new energy level (shell).