Question

the gases of air can be separated by fractional distillation of liquid air because they have different

Answer 1

they have different boiling point. This is known as fractional distillation

Answer 2

Explanation:

fraction distillation is a process of separation of mixtures based on the different boiling points. so, oxygen and nitrogen can be separated by fractional distillation because they have different boiling points

so, answer is boiling points