Fire is a chemical reaction. In a chemical reaction, molecules (themselves composed of a set of atoms) are rearranged in new molecules by creating and/or removing bound between atoms. Creating/removing these bounds will either release or absorb some amount of energy. When the reaction release energy, it is an exothermic reaction. When it absorb energy it is an endothermic reaction. Fire is an exothermic reaction and, like most exothermic reactions, the energy is released as heat.
Fire is a chemical reaction. In a chemical reaction, molecules (themselves composed of a set of atoms) are rearranged in new molecules by creating and/or removing bound between atoms. Creating/removing these bounds will either release or absorb some amount of energy. When the reaction release energy, it is an exothermic reaction. When it absorb energy it is an endothermic reaction. Fire is an exothermic reaction and, like most exothermic reactions, the energy is released as heat.