Question

Atomic numbers of nitrogen, oxygen and fluorine are 7, 8 and 9 respectively. Write the electronic configuration of each element and answer the following question:

Which one of N, O and F has the smallest atomic radius and which one the largest?

Answer 1

Step-1: Introduction

The elements in periodic table are placed in periods and groups. Periods are horizontal rows that has increasing atomic numbers. Groups are vertical columns. There are 7 periods and 18 groups in periodic table.

Step-2: Electronic configuration

Atomic numbers of Nitrogen ($\mathrm{N}$), Oxygen ($\mathrm{O}$) and Fluorine ($\mathrm{F}$) are 7, 8 and 9 respectively.

Electronic configuration of Nitrogen = (2, 5).

Electronic configuration of Oxygen = (2, 6).

Electronic configuration of Fluorine = (2, 7).

Step-3: Atomic radii

Atomic radii are the distance of the electrons in the outermost shell from the atomic nucleus.

It increases from top to bottom in a group and decreases from left to right in a period but is highest for a noble gas.

Since Nitrogen, Oxygen, and Fluorine belongs to the same period 2, the atomic size drops. The reason is due to the rise in proton number and it results in higher electrons attraction.

Therefore, Fluorine has the smallest atomic radius and Nitrogen has the largest atomic radius.