is burning of natural gas i..e CH4+2O2=CO2+2H20

and respiration process are combination reactions?

if it y?combination reactions should have only one product right?

pls answer me clearly expert

The combustion of natural gas is an example of  exothermic reaction.

CH_{4 (g)} + 2O_{2 (g) →}      CO_{2 (g)} + 2H₂O _(g)

Respiration is also an exothermic reaction involving the biological oxidation reaction of food nutrients with oxygen to form carbon dioxide and water with the release of chemical energy.