Answer:
Hydrogen (H2) or Oxygen (O2)
Explanation:
If I get the question right, we are to test for the presence of oxygen or hydrogen.
To test for or detect the presence of oxygen ; Insert a glowing splinter in a container containing the unknown gas, if the splinter pops or if there is a rekindling of the glowing splinter, then oxygen is present or this indicates the presence of oxygen.
To test for or detect the presence of hydrogen ; Insert a flaming splinter in a container or test tube containing the unknown gas, if there is a pop sound or a slight explosion, then the gas present is hydrogen.
