Of the following important statements about the First Law of Thermodynamics, which is CORRECT?
a. Energy cannot be created nor destroyed, but it can be changed from one to another
b. Energy can be created nor destroyed, and also it can be changed from one to another
c. Energy cannot be created nor destroyed, but it can never be changed from one to another
d. It is also called the Principle of Conservation of Matter.
A
C
B
D
The correct answer and explanation is:
The correct answer is A: Energy cannot be created nor destroyed, but it can be changed from one form to another.
The First Law of Thermodynamics is often referred to as the Law of Energy Conservation. It states that energy cannot be created or destroyed in an isolated system. However, it can be transformed from one form to another, such as from kinetic energy to potential energy, or from chemical energy to thermal energy.
This law implies that the total energy in an isolated system remains constant over time. For example, when a car engine burns fuel, the chemical energy in the fuel is converted into mechanical energy (movement) and thermal energy (heat). Similarly, when a substance undergoes a chemical reaction, energy is either absorbed or released, but the total amount of energy before and after the reaction remains the same.
It is important to note that energy transformations are not always 100% efficient. Some of the energy is often lost as heat to the surroundings, which is an example of energy being converted to an unusable form. This principle also plays a role in understanding various processes, such as the operation of engines, refrigerators, or even biological systems like metabolism in organisms.
Option B is incorrect because energy cannot be created or destroyed, contrary to what is suggested. Option C is also wrong because energy can indeed be changed from one form to another. Option D is not correct either since the First Law of Thermodynamics refers specifically to energy conservation, not matter conservation. The conservation of matter is a separate principle, often discussed in the context of chemical reactions.