What occurs during electron capture?

During electron capture, an orbital electron interacts with a proton in the nucleus of an atom, resulting in the conversion of that proton into a neutron. This occurs when the electron is absorbed by the nucleus and facilitates the transformation of a proton to a neutron through a weak nuclear interaction.

This process not only changes the composition of the nucleus by decreasing the number of protons but also leads to a decrease in the atomic number of the element, effectively converting it into a different element. The emitted neutrino that accompanies this interaction is a byproduct, though it is not directly addressed in the question.

The other choices described processes that do not occur during electron capture: ejecting a proton would imply a different kind of nuclear reaction, emitting an alpha particle is characteristic of alpha decay, and splitting a neutron does not accurately describe any known particle interaction relevant to electron capture.