/    /  Atomic Mass and Molecular Mass

Atomic mass:

Atomic mass can be defined as mass of an atom or element.

Molecular mass:

Molecular mass can be defined as mass of an element or molecule.

Here we have to remember atomic masses of  elements from 1 to 30 must and should.

From 1 to 20 elements,

  • For even atomic number we should multiply the atomic number with 2.
  • For odd atomic number we should multiply the atomic number with 2 and add +1
  • For Be,N,Cl,Ar it deviates the above given rule.

Atomic Numbers - i2tutorials

 

For 21 to 30 elements it will follow different rule to satisfy the mass of an atom.

Atomic Numbers - i2tutorials

Based on these values of atomic masses we can able to find the molecular masses.

For Example:

H2O  — 2 ‘H’  AND  1 ‘O’  atoms are present.

For 2 hydrogens  mass is 2 and for 1 oxygen atom,mass is 16

So,2+16=18.

CuSO4—  1 ‘Cu’—-63.5gm

1  ‘S’—-32gm

4    ‘O’—64gm

Totally: 159.5gm