A or B depends on what you mean by lit or glowing but when you place a wooden split in the sample the gas must reignite but there can be some confusion between hydrogen and oxygen mainly because a splint can cause a slight popping sound while it reignites but hydrogen pops are more violent and can most time extinguish the splint.
Conservation of mass can be checked in an experiment . There are three steps to do it in a best way:
1. Weigh all the equipment and materials required in the experiment before the experiment.
2. Avoid spillage and evaporation during the experiment.
3. Weigh all the equipment and materials after the experiment.
If the mass is conserved then weight from step 1 is equal to weight from step 3.
oops pls forgive me I accidentally did the wrong question.
