Atomic radius is measured in?

In a period of a periodic table, the atomic radius falls from left to right and increases from top to bottom. Any spectroscopic technique, including X-ray, can be used to estimate atomic radii.

Summary:

Atomic radius is measured in (A) Micrometres, (B) Nanometres, (C) Millimetres (D) Centimetres

Nanometers (10-9 m) are used to measure the atomic radius. The smallest distance between the nucleus and outermost orbit is called the atomic radius.