The photograph shown was taken during a meeting of the Deutsche Bunsen-Gesellschaft (German Bunsen Society) in 1932 - Leaving Cert Physics - Question 11 - 2021

To find the increase in kinetic energy, we can apply the formula:

$E = mc^2$

1. Conversion between atomic mass unit (a.m.u) and kilograms (kg).
2. Calculate mass defect from the difference in mass before and after the reaction.
3. Convert mass defect to energy using the conversion $1 ext{ a.m.u} = 1.93 \times 10^{-13} ext{ J}$.

This will give the increase in kinetic energy.

Both the G-M tube and solid-state detector are primarily used to detect (ionising) radiation.

A labelled diagram would show:

• Gas/anode: Ionization takes place when ionizing radiation enters the tube.
• Semiconductor/charged gold electroscope: Indicates the presence of charge.
• Electron-hole pair: Created due to ionization.
• Current: Generated due to the movement of charge carriers, leading to a measurable output.

In the gold foil experiment, alpha particles were directed at a thin foil of gold. The observations helped reveal the atomic structure. A labelled diagram would include:

• Alpha source
• Gold foil
• Zinc sulfide screen: Flashes of light recorded.
• Observation: Most particles passed through, some were deflected at large angles.

Observations noted:

• Most particles passed straight through.
• Some were slightly deflected.
• A few went almost straight back, indicating a dense nucleus.

Rutherford concluded that the atom consists of a small, dense nucleus surrounded mostly by empty space where electrons orbit.

Bohr proposed that electrons occupy quantized energy levels, which restricts their orbits. He introduced:

1. Electrons can only exist in specific energy levels.
2. When electrons move between levels, they emit or absorb photons with energy corresponding to the difference between those levels: $E_{photon} = hf = E_n - E_{n'}$