Question

16 Which two gases can not be broken down by chemical means?(1) CO and He (3) Xe and He
(2) CO and NH3 (4) Xe and NH3

Answer 1

The answer is (2) CO and NH3. The chemical reaction can only break down chemical bonds between atoms inside the molecule. The He and Xe is consists of one atom only, so they can not be broken down by chemical means.