Fluorescent paint on a road sign absorbs ultraviolet radiation from sunlight and emits visible light.
The Table shows a simplified model of the energy changes in one atom of the paint.
Table
| Stage | What happens | Energy of the atom in energy units |
|---|---|---|
| start | none | 2.0 |
| 1 | absorbs ultraviolet radiation | 8.0 |
| 2 | emits visible light | 3.5 |
| 3 | emits infrared radiation | 2.0 |
Describe what happens to the atom in stage 1.
Use data from the Table in your answer.
Calculate the energy carried away by the visible light in stage 2 and by the infrared radiation in stage 3.
Explain why the fluorescent sign looks much brighter in daylight than a sign painted with ordinary paint of the same colour.
A student says:
'If the paint absorbed enough ultraviolet radiation, it would emit gamma rays.'
Explain why the student is wrong.
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.