An atom that undergoes radioactive decay and has a large nucleus most likely contains

more neutrons than protons.

more protons than neutrons.

more protons than electrons.

more electrons than protons.

The answer is: more protons than neutrons The stability of the nucleus is based on the ratio of neutrons and protons present in the nucleus. if the number of protons is equal to the number neutrons then the nucleus is stable but in case the number of protons is more than the number neutrons or the other way round the nucleus to gain stability starts interconversion of neutron to proton or electron or decreases proton numbers. In case of nucleus containing high energy, the nucleus releases it. Such nuclei which release energy to gain stability are called radioactive nuclei and the phenomenon is called radioactivity.

More protons than neutrons