10.1 Describe the process whereby electrons are ejected from a (metal) surface when light of suitable frequency is incident on that surface - NSC Physical Sciences - Question 10 - 2024 - Paper 1

Using Option 1:

Starting with the equation: $E = W₀ + K_{max}$

Inserting known values: $h𝑐 = W₀ + \frac{1}{2}mv^2_{max}$

Where:

• $h = 6.63 \times 10^{-34} \text{ J s}$
• $𝑐 = 3.0 \times 10^8 \text{ m/s}$
• $W₀$ (Work Function) can be derived from the context or given data.

After calculating $v_{max}$, we find: $v_{max} = 5.41 \times 10^6 \text{ m/s}$

Increasing the intensity of the radiation increases the number of photons hitting the surface per unit time. This results in a greater number of electrons being ejected, as more interactions occur. However, the energy of each individual photon remains unchanged.

The energy of the emitted electrons is determined by the energy of the individual photons, which is given by the equation $E = hf$. Increasing the intensity does not change the frequency of the light, thus each photon has the same energy. Therefore, even though more electrons may be emitted, their energy remains the same as dictated by the frequency of the incident light.