Question

Which of the following elements has no known stable isotopes?

• A. Carbon
• B. Silver
• C. Radon
• D. Phosphorus
• E. Lead

Answer 1

The correct option is C Radon

Only Radon in given elements has no known stable isotopes.

Carbon $\left(C\right)$ has $15$ known isotopes, from ${}^{8}C$to ${}^{22}C$, 2 of which ${(}^{12}C$ and ${}^{13}C)$ are stable.

Silver has $28$ known isotops. Naturally occurring silver $\left(Ag\right)$ is composed of the two stable isotopes ${}^{107}Ag$ and ${}^{109}Ag$ with ${}^{107}Ag$ being the more abundant.

phosphorus $\left(P\right)$ has $23$ isotopes from ${}^{24}P$ to ${}^{46}P$, only one of these isotopes is stable ${}^{31}P$.

`Lead $\left(Pb\right)$ has four stable isotopes: ${}^{204}Pb{,}^{206}Pb{,}^{207}Pb{,}^{208}Pb$`.