Question

What is an atom?Which Unit is used to measure the size of an atom.​

Answer 1

Atom -The smallest particle of something .

Answer 2

Atom is the smallest unit of matter. The unit Atomic Radius is used to measure the size of any atom.

• All the elements present are said to be made up of microscopic units called  atoms.
• There are different ways to measure the atomic radius of any given atom.
• We know the standard unit of length is meter(m). But due to very small size of the atom we measure the radius in the smaller units as picometer, femtometer, etc.
• For example, the atomic radius of the smallest atom i.e., helium atom is 32pm and atomic radius of the largest atom i.e., caesium is 225pm.
• Another common unit is Angstrom.
• $1 Angstrom = 10^{-10} m$