Quantum Physics: Practice Questions (Form 5 SPM Physics)

E = hf = 6.63 × 10⁻³⁴ × 5.0 × 10¹⁴ = 3.32 × 10⁻¹⁹ J.

E = hc / λ = (6.63 × 10⁻³⁴ × 3.0 × 10⁸) / 6.0 × 10⁻⁷ = 3.32 × 10⁻¹⁹ J.

W = hf₀ = 6.63 × 10⁻³⁴ × 4.5 × 10¹⁴ = 2.98 × 10⁻¹⁹ J.

½mv²max = hf − W = 5.0 × 10⁻¹⁹ − 3.0 × 10⁻¹⁹ = 2.0 × 10⁻¹⁹ J (maximum kinetic energy).

Shining light on a metal can eject electrons, but only if the light's frequency is high enough. This shows light behaves as particles of energy, not just as a wave.

A photon is a single packet, or quantum, of light energy. Its energy depends only on the light's frequency, so higher-frequency light carries more energetic photons.

Ejecting an electron needs one photon with enough energy, which depends on frequency. Red light's photons are below the threshold, so making it brighter only sends more weak photons, none of which can do the job.

The concept that light and matter can show both wave-like and particle-like properties depending on how they are observed.

An electron emitted from a metal surface as a result of the photoelectric effect.

The electromagnetic radiation emitted by an ideal body that absorbs all radiation falling on it, whose spectrum depends only on its temperature.

The smallest discrete amount of a physical quantity, such as energy, that can exist independently.

A single quantum, or particle, of light or other electromagnetic radiation, carrying energy E = hf.

The fundamental constant h relating the energy of a photon to its frequency (E = hf), with a value of about 6.63 × 10⁻³⁴ J s.