Question

The correct order of atomic radii of the elements O, N, S and P is

• A. \(N < P < S < O\)
• B. \(N < O < P < S\)
• C. \(O < N < P < S\)
• D. \(O < N < S < P\)

Hint:

Atomic radius decreases across a period from left to right and increases down a group. Always locate the elements in the periodic table before comparing their sizes.

Answer 1

The Correct Option is D

Step 1: Recall periodic trends for atomic radius.
Across a period (left to right): radius decreases due to increasing Zeff, so N>O and P>S. Down a group (top to bottom): radius increases due to added shells, so P,S>N,O.

Step 2: Arrange by combining trends.
Smallest: O (rightmost in 2nd period), then N (left of O in 2nd), then S (right of P in 3rd), then P (leftmost in 3rd). Complete order: O<N<S<P.

Step 3: Final Answer:
O<N<S<P (option 3).