The air hole of a Bunsen burner should be closed before lighting it to ensure safety and efficiency. Hazards when using a Bunsen burner include igniting flammable materials and the risk of burns.
Before lighting a Bunsen burner, the air hole should be closed to prevent gas buildup and ensure a proper flame structure. This helps in controlling the amount of air mixed with the gas, leading to a more efficient and safer combustion process.
Hazards when working with a Bunsen burner:
https://brainly.com/question/12749566