Find the ratio by

(a) C₂H₅OH

The ratio by mass = 2XC : 6XH : O

= 2X12 : 6 : 16

= 24 : 6 : 16

= 12 : 3 : 8

(b) NH₃

The ratio by mass = N : 3 × H

14 : 3

OR

The number of atoms constituting a molecule is known as its atomicity. On the basis of atomicity, the elements may be classified as follows: