Electron Configurations of lons ③ 19 01 23 Review Constants Periodic Table When an atom forms an ion, it will gain or lose electrons to attain a more stable electron configuration, frequently that of a noblo gas. Nonmetals tend to form anions by gaining electrons, which enter the lowest energy unoccupied orbital. Metais tend to form cations by losing electrons. Main group motals lose electrons in the reverso order of filling. Transition metals, however, lose s electrons first. Part A In the ground-state electron configuration of Fe, how many unpaired electrons are present? Express your answer numerically as an integer. View Available Hint(s) Submit Part B Enter the electron configuration for the lon most likely formed by phosphorus Express your answer in the order of orbital filling as a string without blank space between orbitals. For example, the electron configuration of Li could be entered as 15″225″1 or (He]2s 1. View Available Hint(s) electron configuration Pion: Submit