Across
- 3. the minimum amount of energy needed to eject a (photo)electron from the surface of a metal (4,8)
- 5. In Einstein’s photoelectric equation Ekmax is the maximum kinetic energy of an ejected _____________ (8)
- 6. number of spectral lines produced by this element? DIAGRAM
- 9. photons (or waves) of a single wavelength (13)
- 11. a small, cheap, efficient type of laser (13)
- 12. the smallest possible amount of light energy (6)
- 14. rainbow spectrum with dark lines (10)
- 16. the name of the process where a photon of sufficient energy is absorbed by an electron in the ground state, allowing it to be promoted to the topmost energy level in a LASER system
- 17. a large, expensive, inefficient type of LASER that utilises mirrors at each end (3)
- 18. type of spectrum showing a dark background with coloured lines (8)
- 19. a device used to detect the presence of electrical charge (12)
- 20. energy necessary to remove an electron from an atom (hint: not φ) (10)
- 21. relationship between the incident photon and emitted photon in stimulated emission (8)
Down
- 1. the emission of a photon from an excited atom, triggered by an incident photon of energy equal to the energy gap between the excited state and a state of lower energy in the atom (10,8)
- 2. In a LASER, how does the length of time spent in the topmost energy level compare to the time spent in the one directly below it? (7)
- 4. name for a ‘near stable’ or ‘almost stable’ energy level in a LASER (10)
- 6. type of emission from an unstable energy level to one below it
- 7. in terms of energy, what is the meaning of hf? (6,6)
- 8. (9,9) the minimum frequency for which (photo)electrons are emitted (symbol fo)
- 10. when more electrons are in a higher energy state than an (adjacent) lower energy state (10,9)
- 13. DIAGRAM (9, 10)
- 15. gradient of a kinetic energy vs. frequency graph (6,8)