chemistry help?

Question

what is the electron configuration (short form) and number of unpaired electrons of 29Cu^+2? Explain please.

Answer 1

1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d7.
Cu +2 means that it has lost 2 electrons from its normal number to get the positive charge. It usually has 29 electrons total so it will have 27electrons in the charged ion. In d shells there are 5 orbitals and hunds rule says there will be maximum paralell spins so in the 3d7 you will have ^V ^V ^ ^ ^ or 3 unpaired electrons.