Element 38 in our International Year of the Periodic Table series is strontium. Named after Strontian, a village in Scotland where it was discovered, strontium finds use in glow-in-the-dark paints and in toothpastes.
Glow-in-the-dark paints usually contain either zinc sulfide or strontium aluminate. Both of these give the paint phosphorescent qualities; this means it absorbs light, then slowly re-emits it over a period of time. Strontium aluminate gives a brighter glow than zinc sulfide, and it is commonly used on watch faces and glow-in-the-dark toys.
Strontium also pops up in some toothpastes in the form of strontium chloride. In particular, it’s used in toothpastes aimed at people with sensitive teeth. It forms a barrier in exposed tubules in the dentin (the layer of the tooth underneath the enamel), which prevents stimulation of nerve endings which can cause teeth to feel sensitive.
Finally, strontium can also be used as a source of electricity. The heat produced by the radioactive decay of one of its isotopes, strontium-90, can be converted into electricity by a type of electrical generator. These generators are typically used for some space vehicles, remote weather stations, and navigation buoys.
Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.