) When coal is burned completely into carbon dioxide and other gases, the total amount of matter of the gases .

This question is incomplete

Explanation:

This question is incomplete. The process described in the question is combustion; where a substance burns completely in excess oxygen to produce mainly carbon dioxide and then other gases. There is no chemical equation for this particular combustion reaction because coal is a mixture.

However, the amount of the matter of the gases produced from this combustion must be equal to the total number/amount of matter that constitutes the coal because of the law of conservation of matter that states matter can neither be created nor destroyed.

d. air pressure decreases as altitude increases.

small = small current large mag large current