Using the drop down choices below, complete the ground state electron configuration for an atom of selenium. Note: If an orbital doesn't contain electrons, select a value of "0" from the list (for the purposes of this question only). [Ar] 4s ◆ 3 0 4p ◆

Write the electron configuration for the ground state of Hg2+ (mercury 2+). Use the noble gas shortcut. Since Canvas doesn't support superscripts and the like, type in the electron configuration with a space between each sublevel, and without special formatting. For example, [He]2s2p? would be typed in the answer box as "[He] 2s2 2p2".

When looking at the list of electron configurations of elements up to Z = 103. Some do not follow the Aufbau principle. What do these elements have in common? A) They are all transition metals. B) They all have at least one half-filled shell. C) They all end in d5 or d10. D)They do not have anything in common

The Auf Bau Principle, Hund's rule, and the Pauli exclusion principle are used to determine the lowest energy electron configuration of an atom, called the ground state; any other possible configuration is higher in energy, an excited state.   Which of the following valence shell electron configurations are excited states?           5s   5px   5py   5pz   4dz2   4dx2-y2   4dxy   4dyz   4dxz   (1)   ­ up, down   ­up               up­   up­   (2)   up, down­ ¯             ­   ­up   ­up   (3)   ­ ­up, down           up ­ up ­ up ­   (4)   ­ ¯up, down   ­up   ­up   ­up             1, 2, and 3 (b) 1 and 4      (c) 2 only        (d) 4 only        (e) 3 only   answer is B. i need explanation.