Question

what is the precaution to be taken while doing the activity to know the reaction of oxygen with metals and nonmetals

Answer 1

Many non-metals and metals react violently with oxygen. For example hydrogen burns explosive with oxygen, magnesium burns with extreme heat with oxygen, an some metals such as steel produce sparks on burning in the presence of oxygen. Here therefore are some of the precautions that should be taken while handling these experiments: 
1) Wear protective clothing
2)Wear gloves
3)Put on goggles before doing these experiments
4)Use tongs to handle the metals to be burnt