Chapter 3: Atoms and Molecules

An atomic mass unit is a unit of mass used to express the weights of atoms and molecules where one

atomic mass is equal to 1/12th the mass of one carbon-12 atom.

Firstly, atoms are minuscule in nature, measured in nanometers. Secondly, except for atoms of noble

gases, they do not exist independently. Hence, an atom cannot be visible to the naked eyes.