The Absorption & Emission of EM Radiation (OCR GCSE Physics A, Combined (Gateway Science Suite)): Revision Notes
📚 Revision Notes
4.1.2 The Absorption & Emission of EM Radiation
infoNote
The absorption of electromagnetic radiation would cause electrons to become 'excited' and move further from the nucleus to a higher energy level. The emission of electromagnetic radiation would cause electrons to move closer to the nucleus, to a lower energy level.
Therefore, atoms and particles in the nuclei can absorb and emit electromagnetic waves over a wide range of frequencies.
Atoms and Electromagnetic Radiation
- When electrons change orbit (move closer or further from the nucleus):
- Move to a higher orbit (further from the nucleus):
- The atom has absorbed EM radiation.
- Fall to a lower orbit (closer to the nucleus):
- The atom has emitted EM radiation.
- If an electron gains enough energy, it can leave the atom to form a positive ion.