Question

how do you get a yellow flame?
o gas tap off, collar open
o air hole closed, gas tap fully open
o air hole open, gas tap half open

Explanation:

A yellow flame in a Bunsen burner is produced when there is incomplete combustion. This occurs when the air - hole is closed, restricting the supply of oxygen, and the gas tap is fully open, allowing a large amount of gas to flow.

Answer:

B. Air hole closed, gas tap fully open