Answer
a. $O^{2-} = 1s^{2} 2s^{2} 2p^{6}$
b. $Br^{-} = [Ar] 4s^{2} 3d^{10} 4p^{6}$
c. $Sr^{2+} = [Ar] 4s^{2} 3d^{10} 4p^{6}$
d. $Co^{3+} = [Ar] 3d^{6} $
e. $Cu^{2+} = [Ar] 3d^{9} $
Note: b and c are just the configuration of [Kr].
Work Step by Step
Write the electronic configuration of each of the atoms according to electronic structure.
