The table gives the allowed energy levels of an electron in an atom. The energies are measured relative to level A.
| Energy level | Energy (× 10⁻¹⁹ J) |
|---|---|
| A | 0.0 |
| B | 2.0 |
| C | 4.8 |
| D | 8.8 |
The electron is initially at level B. The atom absorbs photon P, which has an energy of 6.8 × 10⁻¹⁹ J.
Explain which energy level the electron reaches after photon P is absorbed.
The electron returns to level A in two transitions. It first moves to level C, emitting photon Q. It then moves from level C to level A, emitting photon R.
Calculate the energy of each emitted photon.
Explain which emitted photon has the higher frequency.
104 exam-style questions on Edexcel GCSE Physics 5.4 Uses and dangers of EM radiation, covering 5.4.1 Dangers of electromagnetic radiation, 5.4.2 Uses of electromagnetic radiation, 5.4.3 Radio waves and oscillations in circuits, and 5.4.4 Changes in atoms and nuclei generating radiation. Each one has a worked solution and a mark scheme showing where the marks go.