Question

Which of the following isotopes is most likely to be radioactive?

O 12 protons and 16 neutrons, because it has even numbers of protons and neutrons.
O 2 protons and 8 neutrons, because it has a magic number of both protons and neutrons.
O 40 protons and 59 neutrons, because it has an odd number of neutrons.
O 29 protons and 35 neutrons, because it has odd numbers of protons and neutrons.

Answer 1

The isotope with 40 protons and 59 neutrons is most likely to be radioactive because it has an odd number of neutrons, which generally makes it less stable compared to isotopes with even numbers or magic numbers of protons and neutrons.

Step-by-step explanation:

The isotope most likely to be radioactive is the one with 40 protons and 59 neutrons, because it has an odd number of neutrons.

Isotopes with an odd number of neutrons tend to be less stable and more likely to be radioactive. This aligns with the general observations that isotopes with even numbers of protons and neutrons are more likely to be stable, and those with magic numbers of protons and neutrons are especially stable.

Furthermore, isotopes with odd numbers of both protons and neutrons are predicted to be unstable, and therefore radioactive, as seen with phosphorus-30 (30P).