In 1986, there was an accident that led to an explosion at the Chernobyl Power Plant in what was then the Soviet Union. Soon after, people started to notice something horrifying. A radioactive element released during the explosion was replacing calcium in people's teeth and bones! The element had chemical properties similar to calcium. Which elements are likely to have similar properties to calcium because they have the same number of valence electrons as calcium?

Radium (Ra)

Explanation:

The nuclear fuel at Chernobyl was uranium-235. However, one of the decay products of uranium-235 is radium.

Radium is chemically similar to calcium since it has two valence electrons and is the heaviest and last member of group 2.

Owing to its chemical similarity to calcium, it was able to replace calcium in people's teeth and bones. Radium is radioactive, the half life of Ra-226 is about 1602 years.

Other elements of group 2 are; beryllium, magnesium, strontium and barium.