The symbol "ħ" represents the reduced Planck constant in physics, a fundamental quantity in quantum mechanics. It is defined as the Planck constant divided by 2\pi and is used to describe the scale of quantum effects. The value of ħ is approximately 1.055 \times 10^-34 \, \textJs. In quantum mechanics, ħ plays a crucial role in equations such as the Schrödinger equation, which describes how quantum states evolve over time. It is essential for understanding phenomena like wave-particle duality and the behavior of particles at the atomic and subatomic levels, linking it to concepts like quantum theory and wave functions.