Question

10. a) Helium is preferred to hydrogen for filling balloons
because it is :
(i) lighter than air (ii) almost as light as hydrogen
(iii) non-combustible (iv) inflammable.​

Answer 1

Answer:

3). non combustible

Explanation:

the the airship in old times used to use hydrogen gas instead of helium because it was cheap and very effective but it was very prone to explosions as hydrogen is combustible

Answer 2

Answer:

(i). Lighter than Air

(ii). Almost as light as Hydrogen

(iii). Non-combustible.

The non - combustibilty of Helium gas was the primary reason why Hydrogen gas was replaced with Helium gas.