Which of the following is NOT a radioactive material?

Question

Question

This question was previously asked in

Territorial Army Official Paper II (Conducted on 31 Jul 2016)

Answer 1

Sodium is NOT correct.

Most of the radioactive materials belong to the 6th,7th, and actinide periods of the modern periodic table.
But the Sodium metal belongs to the 2nd period of the modern periodic table.
That's why Sodium is not a radioactive chemical compound and the correct answer to this question is option 4.

Key Points

Radioactivity is a part of nature. Everything is made of atoms.
Radioactive atoms are unstable; that is, they have too much energy.
When radioactive atoms spontaneously release their extra energy, they are said to decay.
All radioactive atoms decay eventually, though they do not all decay at the same rate.
After releasing all their excess energy, the atoms become stable and are no longer radioactive.
The time required for decay depends upon the type of atom.
Examples of radioactive materials
- Radioactive elements such as uranium, thorium, and plutonium, radium.

Important Points

Sodium is a highly reactive metal and reacts vigorously with the oxygen, carbon dioxide, and moisture present in the air such that it may even cause a fire.
To prevent this explosive reaction, Sodium is kept immersed in kerosene because Sodium doesn't react with kerosene.