What does an electron and neutron have in common

They have the same mass and are both located in the nucleus of the atom.

Very little except that they are both particles that make up atoms. The electron is a lepton with very little mass and a negative electrical charge. The neutron is a much more massive , chargeless particle (a hadron) which with protons ( positively-charged hadrons ) forms the atomic nucleus.

Ithink is a because if say increased in electronegativity