1. a Calculate the energy of the following photons, giving your answers in Joules and electronvolts:
- i A radio wave photon of wavelength 2.5 m
- ii An infrared photon of wavelength 6.0μm
- iii A visible photon of wavelength 623 nm
- iv An X-ray photon of wavelength 1.5×10−10 m
2. b A 5-mW laser emits light of wavelength 630 nm. Calculate the
- i energy of a photon of light at this wavelength.
- ii number of photons emitted by the laser in 1 s.