Question

Which is not true about noble gases?
A.They are non-metallic in nature
B.They exist in atomic forth
C.They are radioactive in nature
D.Xenon is the most reactive among these

Answer 1

Hint: Noble gases exist in periodic columns in the same group because they have the same type of characteristics. They exist in group 18th, the last group of the periodic table. All the noble gas elements have their outermost orbit fully filled, so they are not much reactive.

Complete answer:
The correct answer to this question is option C, noble gases are not radioactive in nature. Let us know about noble gases a little bit first to know how they are not radioactive.
Noble gases, also known as inert gases, are chemically inert and they form the 18th group of the periodic table. They are odourless, colourless and are monatomic with very little chemical reactivity.
These gases are highly unreactive but they might react with other elements under extreme conditions. Their non-reactivity comes from their outermost orbit being completely filled, as they are filled they are stable in nature. So, they do not tend to react naturally.
Those being non-radioactive comes from the reason that they are highly stable. Although Radon is a radioactive noble gas, it is considered as an exception.
The statements given in the other options are true, noble gases are non-metallic in nature, they exist in nature in atomic form and Xenon is the only noble gas which can react chemically and does not require extreme conditions.
And, only one noble gas is radioactive, so the statement does not stand true in option C.

Note:
Although Oganesson is a radioactive noble gas, it is not accounted for here because it is synthetically produced and does not occur in nature. Also, noble gases except helium and neon can react with other elements but under only extreme conditions.