Atomic mass:
Atomic mass is also
called as atomic weight. Atomic mass is determined by using the relative
abundance of the isotopes which are naturally occurring element. It’s a sum of the all the protons, neutrons
and electrons in an atom (Figure 1).
Atomic mass of the atom shows the size of an atom.
Examples of Atomic Mass:
- 6C12:
Carbon atom contains six protons
and six neutrons, so the atomic mass of the carbon is 12.011.
- 1H1: Hydrogen
having the lowest atomic mass which is 1.0079. Hydrogen atom contains a
proton and electron; protium is the most common isotope of the hydrogen
atom.
Unit of atomic mass: it is an atomic mass unit (amu),
Calculation for atomic mass:
Where,
|
Isotope |
Percentage natural abundance |
Molar mass |
|
1H |
99.985 |
1 |
|
2H |
0.015 |
2 |