The answer is burning paper
The answer can be explained when you burn something cleanly (with a very hot item) or not. With a candle lots of Carbon dioxide is producted but when using a bunson burner hardly any CO2 is produced.
Answer:
Osmium
Explanation:
The metals conduct electricity the best, in this question the metal would be osmium.
It is -2 because the charge will be at zero and electrons lower the charge
