The equation E=mc², proposed by Albert Einstein, relates energy (E) to mass (m) and the speed of light (c). It states that energy is equal to mass multiplied by the speed of light squared. However, it's important to understand the context in which this equation applies.
When water is heated, its energy increases due to the input of thermal energy. This increase in energy does not result in a significant change in mass. The equation E=mc² is applicable in the context of nuclear reactions or when there are significant changes in energy at the atomic or subatomic level. In such cases, a small amount of mass can be converted into a large amount of energy or vice versa.
In the case of heating water, the energy increase primarily occurs at the molecular level, involving the kinetic energy of water molecules. It involves changes in the vibrational, rotational, and translational energies of the molecules. However, the total mass of the water molecules remains essentially unchanged. The energy gained by the water is equivalent to the energy transferred to it, but it does not result in a significant change in mass.
So, in the context of everyday processes like heating water, the mass remains nearly constant, while the energy increases. The equation E=mc² is not directly applicable to these situations, but it is a fundamental relationship in physics that describes the conversion of mass and energy in certain extreme scenarios, such as nuclear reactions or particle interactions.