Light - UV - 16+
This collection explores Ultraviolet light, suitable for ages 16+.
About ultraviolet light: Ultraviolet (UV) light is an electromagnetic radiation with a wavelength from 400 nm to 100 nm, shorter than that of visible light but longer than X-rays. Though usually invisible, under some conditions children and young adults can see ultraviolet down to wavelengths of about 310 nm, and people with aphakia (missing lens) can also see some UV wavelengths. Near-UV is visible to a number of insects and birds. UV radiation is present in sunlight, and is produced by electric arcs and specialized lights such as mercury-vapor lamps, tanning lamps, and black lights. Although lacking the energy to ionize atoms, long-wavelength ultraviolet radiation can cause chemical reactions, and causes many substances to glow or fluoresce. Consequently, biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules.
Resources in this collection:
- Photoelectric Effect: Produced by the National STEM Centre and the Institute of Physics, this video demonstrates how to use a gold-leaf electroscope, zinc plate and an ultraviolet light source. The zinc plate is placed onto the top of the electroscope and it is given a negative charge. The electroscope can be discharged when ultraviolet light is shone onto the zinc plate. This is due to the UV light photons causing the discharge of electrons from the zinc plate. The photoelectric effect helps to illustrate the wave-particle duality of light.
- Risky radiation: A Catalyst article comparing mobile phones and UV sunbeds. Mobile phones emit radiofrequency (RF) radiation. Tanning beds emit ultraviolet (UV) radiation. These are both types of non-ionising radiation. In recent years both have received considerable media coverage and they are emotive topics for the general public.
- Ultraviolet/visible spectroscopy: This resource, from the Royal Society of Chemistry, provides the background theory for ultraviolet/visible (UV/Vis) spectroscopy. It includes an explanation of the absorption laws and how the spectrometer works.
