Question

Which of the following gives the correct increasing order of the atomic radii of $\mathrm{O},\mathrm{F}\mathrm{and}\mathrm{N}$?

• A. $\mathrm{O},\mathrm{F},\mathrm{N}$
• B. $\mathrm{N},\mathrm{F},\mathrm{O}$
• C. $\mathrm{O},\mathrm{N},\mathrm{F}$
• D. $\mathrm{F},\mathrm{O},\mathrm{N}$

Answer 1

The correct option is D

$\mathrm{F},\mathrm{O},\mathrm{N}$

Explanation for correct option:

D. $\mathrm{F},\mathrm{O},\mathrm{N}$

Atomic radius:

• “The atomic radius is the distance between an atom's nucleus and outer electron shell.”
• Atomic radius decreases across a period as the valence electrons are being added up to the same shell. The increase in nuclear charge attracts the electrons more strongly, which will pull them closer to the nucleus.
• While moving down the group, the atomic radius increases as the number of energy levels increase as there is an increase in the number of electrons.
• Atomic radius increases from left to right across a period.
• The trend for atomic radius for oxygen, nitrogen, and fluorine is given as:

$\mathrm{F}<\mathrm{O}<\mathrm{N}$

• $\mathrm{N}\left(7\right),\mathrm{O}\left(8\right)\mathrm{and}\mathrm{F}\left(10\right)$ are in increasing order of atomic numbers.

Explanation for incorrect options:

The increasing order of atomic radius is given as $\mathrm{F},\mathrm{O},\mathrm{N}$. Thus, options A, B, and C are incorrect.

Hence, the correct option is D i.e. $\mathrm{F},\mathrm{O},\mathrm{N}$.