Which is which or what is what?

By Hanham High

In this film you will see, a group of students trying an experiment to test which gases are which and what gases are what. Please don't try this at home as the gases can be very dangerous and powerful. Please watch it, but don't do it.

 

Question

Which is the gas that is tested for the using the squeaky pop?

Answers

(a) Carbon Dioxide
(b) Helium
(c) Oxygen
(d) Hydrogen