Hand sanitizing station standb. The ground state electron configuration of the ion must be: 1s22s22p63s23p64s03d2; There are 6 electrons in s orbitals. c. 12 d. 2. e. From the mass, this is the isotope Cr. There are 26 neutrons in the nucleus. f. 1s22s22p63s23p64s13d5 is the ground state electron configuration for Cr. Cr is an exception to the normal filling order. 123. An impossible electronic configuration there is no 2d sublevel that can hold 10 electrons E 29. The ground-state configuration for the atoms of a transition element (E) has d orbitals, but (D) is excited state B 30. The ground-state configuration of a negative ion of a halogen Cl gained one e– for Ar configuration B 31.