Final answer:
The statement is True; heat, oxygen, and fuel are indeed the three required elements for a fire to occur as they form the fire triangle, fundamental for the combustion process.
Step-by-step explanation:
The statement that heat, oxygen, and fuel are the three elements required for a chemical reaction that causes a fire to start is True. These three components form what is known as the fire triangle and are essential for combustion to occur. Heat is the energy source needed to initiate and maintain a fire. Fuel is a combustible material that the fire consumes, characterized by properties such as moisture content, shape, and size. Finally, oxygen from the air, which is approximately 21% of the atmosphere, sustains the chemical processes during fire through oxidation, where the fuel reacts with oxygen to release heat and generate combustion products. Thus, without any one of these elements, a fire cannot occur.