Which element’s atoms have the greatest average number of neutrons? germanium (ge) arsenic (as) selenium (se) bromine (br)

The answer is selenium (Se)
selenium is a non metallic chemical element, member of the group 16 of the periodic table. Its atomic number 34 having 34 protons, 45 neutrons and 34 electrons. Its similar to sulphur in its form and compounds, converts light into electricity and decreases in electrical resistance with increased illumination among others.

The charge of an ion with 55 protons and 52 electrons is +3. the reason is because protons are positive, and there are three more than the amount of negative electrons.