What are two main products of the combustion of methane and other fossil fuels?

Answer is: main products of the combustion of methane and other fossil fuels are carbon(IV) oxide and water.
Balanced chemical reaction of combustion of methane:
CH₄ + 2O₂ → CO₂ + 2H₂O.
In this combustion reaction, carbon is oxidized (from -4 to +4 oxidation number) and oxygen is reduced (from 0 to -2 oxidation number).

If a simple combustion reaction is given to methane, it would mean that it is possible to burn it. The combustion process consists of a reaction between methane and oxygen in the air. When such reaction takes place, the by products are: carbon dioxide and water--- and also energy.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom