Question

please answer this please​

Answer 1

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Exaplanation

21(i). we can't make call now by burying trees and soil to use it next year because it takes millions of years for the process of conversion

21(ii)Coal is formed only when the wood is very deep into the earth because under the high pressure and high temperature only that plants can get converted to coal

21(iii)When heated in air, coal burns and produces mainly carbon dioxide gas. When coal is burned, it reacts with the oxygen in the air. This chemical reaction converts the stored solar energy into thermal energy, which is released as heat. But it also produces carbon dioxide and methane.

21(iv)As coal is formed from the remains of vegetation called is called as a fossil fuel