1. Radium is the heaviest of the alkaline earth metals.
2. It is highly radioactive and can be extremely dangerous.
3. Due to its oxidation, it changes from a silvery white color to black when exposed to air.
4. Radium-226 has a half-life of 1602 years, the longest of all radium isotopes.
5. Radium exposure, which could result from inhaling or swallowing, could cause cancer, anemia, cataracts, and even death.
6. Radium is in the same group as calcium and is therefore sometimes used to treat bone cancer through emitting alpha particles that kill cancerous cells.
7. Radium was used to paint the numbers and hands in clocks to be visible in the dark. However, this was stopped after many factory workers died from exposure.
8. We are constantly exposed to small amounts of radiation as it is naturally occurring in our environment.
9. Marie and Pierre Curie's laboratory notebooks are still too radioactive to be handled today, due to their work with radium.
10. Radium can be found in everyday products, including wristwatches and toothpaste.
11. It has an abundance of roughly one part per trillion in the Earth's crust. This makes it the 84th most abundant element in the crust.
12. Radium is created from the decay of the uranium atom, which then turns into several other unstable elements before finally ending in the element lead.
13. The name of this element comes from the Latin world "radius", which means ray.
14. Radium has no known biological role because it is toxic due to its radioactivity.
15. An equivalent amount of radium would be three million times more radioactive than uranium.
16. Radium was the first radioactive element to be made synthetically.
17. It is a solid state at room temperature.
18. A sample of radium metal maintains itself at a higher temperature than its surroundings because of the radiation it emits.
19. At the time of the Manhattan Project in 1944, the "tolerance dose" for workers was set at 0.1 microgram of ingested radium.
20. Currently, other than its use in nuclear medicine, radium has no commercial applications. Formerly, it had other uses but since the toxicity is known now, less dangerous isotopes are used instead radioluminescent devices.