Question

what is atom? Describe about atomic mass?​

Answer 1

Answer:

The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.

Answer 2

$\huge\sf\underline{Atom:-}$

Atoms consist of a nucleus made of protons and neutrons orbited by electrons. ... We now know that atoms are made up of three particles: protons, neutrons and electrons — which are composed of even smaller particles, such as quarks.

$\huge\sf\underline{Atomic mass}$

The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope.