How does fire produce heat?
A crackling fire is somewhat like a busy market where something is exchanged for something else. In a market, we exchange money for food and other items. In the fire, fuel is exchanged for flames and heat. It is a chemical change that yields heat energy by converting wood to ashes. A blazing fire is a very busy chemical operation though most of the activity is invisible. Its original chemicals are m0lecules of wood, coal or other substances used as fuel. The chemical changes occur within the fuel molecules, and in this scaled down world the changes are stupendous, because these molecules are shattered and exist no more in their original forms. Let’s fancy, for example, a friendly fire of flaming logs. Its fuel is wood, made mostly of cellulose molecules. Like all molecules, they are packages of atoms bound together with ties of energy. Cellulose is a carbohydrate related to the sugary and starchy chemicals. Each of its molecules is a union of atoms of carbon, hydrogen and oxygen. The e
