Question

what is atom? What is atomic mass? ​

Answer 1

atom is the smallest substance which take part in the chemical reaction. the average of all isotopes of a element is known as atomic mass

Answer 2

Answer:

Atom is the smallest particle of a chemical element that can exist.

The mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.