Planck's constant, denoted as h, is a fundamental physical constant that is used to relate the energy of a photon to its frequency. It is a crucial value in quantum mechanics and is often expressed in units of joules per second (J s) or electron volts per second (eV s).
Planck's constant is related to energy through the equation E = hf, where E is energy, h is Planck's constant, and f is frequency. This means that the energy of a photon is directly proportional to its frequency, with Planck's constant serving as the proportionality constant.
The two different units, J s and eV s, are used to express Planck's constant in different systems of measurement. J s is the standard unit in the International System of Units (SI), while eV s is often used in the field of quantum mechanics and is equivalent to 1.602 x 10^-19 J s.
To convert from J s to eV s, simply multiply the value in J s by 6.241 x 10^18. To convert from eV s to J s, divide the value in eV s by the same conversion factor.
Planck's constant is important because it is a fundamental constant that helps us understand the behavior of subatomic particles and the nature of energy. It is used in various equations and calculations in quantum mechanics, and has been crucial in the development of technologies such as lasers and semiconductors.