Question

give reason for following assertions .
a) ammonia is a compound
b) air is a mixture , not a compound
c) tap water is a mixture , not a compound

Answer 1

Ammonia is a chemical compound formed by two elements nitrogen and hydrogen that they are bonded together and these elements cannot be separated physically.
Air is a mixture which consist of more elements mixed together and can be separated. Air contains nitrogen, oxygen, carbondioxide, helium like gases.
Tap water is a mixture because it consist of water, sedimented impurities like sand, mud, dust particles. These components can be separated.