7.4 Mass-Energy Equivalence

Mass-Energy Equivalence

• Mass-energy equivalence is the concept that mass and energy are interchangeable and can be converted into each other. It is described by the famous equation E=mc^2, where E is energy, m is mass, and c is the speed of light.
• The mass-energy equivalence equation shows that the energy of a body is equal to its mass multiplied by the speed of light squared. This means that even a small amount of mass can be converted into a large amount of energy.
• The mass-energy equivalence equation was first proposed by Albert Einstein in his theory of relativity and was later confirmed by numerous experiments. It is a fundamental principle of physics that has been confirmed to high precision.

• Disintegration energy is the energy required to break down a nucleus into its constituent protons and neutrons. It is a measure of the strength of the forces that hold the nucleus together.
• The disintegration energy of a nucleus is equal to the energy required to separate the protons and neutrons in the nucleus. It is a measure of the stability of the nucleus.
• The disintegration energy of a nucleus can be calculated using the equation DE = Mc^2 - M1c^2 - M2*c^2, where DE is the disintegration energy, M is the mass of the nucleus, M1 is the mass of the protons, M2 is the mass of the neutrons, and c is the speed of light.
• The disintegration energy of a nucleus is a positive value, which means that energy is required to break the nucleus apart. It is a measure of the stability of the nucleus and is related to the binding energy of the nucleus.

• Exothermic reactions are chemical reactions that release heat energy to the surroundings. These reactions are accompanied by an increase in the temperature of the surroundings.
• Endothermic reactions are chemical reactions that absorb heat energy from the surroundings. These reactions are accompanied by a decrease in the temperature of the surroundings.
• Exothermic reactions are reactions in which the products have less energy than the reactants. The difference in energy between the reactants and products is released as heat to the surroundings.
• Endothermic reactions are reactions in which the products have more energy than the reactants. The difference in energy between the reactants and products is absorbed from the surroundings as heat.
• The heat absorbed or released in a chemical reaction is called the heat of reaction. The heat of reaction can be positive, negative, or zero. A positive heat of reaction indicates that heat is released to the surroundings, while a negative heat of reaction indicates that heat is absorbed from the surroundings. A zero heat of reaction indicates that no heat is exchanged with the surroundings.