Which of the following is not among the 'rare earth metals' used in manufacturing electrical and electronic components?
- AScandium (Sc)
- BLanthanum (La)
- CCerium (Ce)
- DRadium (Ra)
Show answer and explanation
Correct answer: (d) Radium (Ra)
Explanation
The rare earth elements are 17 metals: the 15 lanthanides (lanthanum to lutetium) together with scandium and yttrium. They are used in magnets, phones, screens, batteries and other electronics.
Radium (Ra) is not one of them. It is a radioactive alkaline earth metal of Group 2, discovered by Marie and Pierre Curie in 1898.