Across
- 3. occurs when an electron in the atom gains enough energy to escape from the nucleus of the atom.
- 4. occurs when an electron in an excited atom moves back to a lower energy level.
- 6. energy arriving per unit area per unit time.
- 7. a constant relevant to this topic; the constant used to explain the experimental data from the ultraviolet catastrophe
- 12. the work done to accelerate an electron through a voltage of 1V.
- 13. the type of spectrum which contains photons of all frequencies e.g. from a tungsten filament lamp.
- 17. is the voltage at which the highest kinetic energy electrons in a vacuum photocell do not make it to the other side so current in said photocell just falls to zero (8,9)
Down
- 1. (7) discrete quanta (packets) of energy of electromagnetic radiation.
- 2. (4,8) the type of spectrum that contains photons of only certain discrete frequencies e.g. from a discharge tube. The frequencies correspond to the possible energy level changes in atoms of this element where hf=ΔE.
- 5. (4,10) the type of spectrum that has certain discrete frequencies missing. e.g. light from a star that has passed through cooler gas. The frequencies correspond to the possible energy level changes in atoms of this element hf=ΔE.
- 8. (n=1) is the lowest energy level of the atom.Its energy in eV is negative, showing how much energy would be required for ionisation (6,5)
- 9. a type of microscope with which produces images with a much better resolution than visible light
- 10. unit of frequency
- 11. is the minimum energy required for an electron to escape a metal surface.
- 14. occurs when an electron in the atom gains exactly the right amount of energy to move to a higher energy level.
- 15. unit of power
- 16. the SI unit for energy