Question

Which best describes how combustion works?

Answer 1

Answer: A) It breaks and forms bonds of fuel to release thermal energy.

Explanation:

Chemical energy is the energy stored in the bonds of molecules.

Thermal energy is the energy possessed by a body by virtue of its temperature.

Combustion is a chemical reaction in which a fuel is burnt in the presence of oxygen to form carbon dioxide, water and heat.

$C_xH_y+x+\frac{y}{4}O_2\rightarrow xCO_2+\frac{y}{2}H_2O+Energy$

Thus the chemical energy stored in the bonds of reactants is converted to thermal energy and heat is released in the combustion reaction.

Answer 2

The answer is A, it breaks down and releases thermal energy.