<p align="right">Last Update: <font color="#4f81bd">November 25, 2024</font></p> ## BIG IDEA - A fundamental [[Physical constant|physical constant]] of foundational importance to [[Quantum mechanics|quantum mechanics]]. ### Symbol $h$ ### Value $6.63 \ x \ 10^{-34} \ \frac{J}{s} \tag{1}$ ### Usage - *Planck's constant*: More informal, historical emphasis. - *Planck constant*: Formal, preferred in scientific and SI contexts. - This usage aligns with how other constants are named, such as Boltzmann constant, Coulomb constant ### Reduced Planck constant A fundamental physical constant used in quantum mechanics to represent the quantization of energy, angular momentum, and action. ### Definition of h-bar $\hbar \ = \ \frac{h}{2 \pi} \tag{2}$ ### Related Topics --- [[Home|Home]] | [[Quantum mechanics]] | [[Notes Vault/Physics Notes Vault/Quantity of Motion/Quantum Mechanics/Blackbody Radiation|Blackbody Radiation]] | [[Photoelectric Effect]] | [[Atomic Theory]]