Imagine this scenario. You walk into your living room. You sit down on the couch. You pick up the TV remote but accidentally drop it. You then get up to go get the remote. With remote control in hand, you make your way back to the couch. While walking you notice the TV is not plugged in. This is not your day. Finally, with the TV plugged in and you settle on the couch. You press buttons on the remote to turn it on and change the channel. You begin to watch the Ravens play football. Does this scenario use contact, non-contact or both forces? Use evidence from the scenario and today's class to identify the forces used. Make sure to include at least 3

Challenge question: this question is worth 6 points. as you saw in problem 9 we can have species bound to a central metal ion. these species are called ligands. in the past we have assumed all the d orbitals in some species are degenerate; however, they often are not. sometimes the ligands bound to a central metal cation can split the d orbitals. that is, some of the d orbitals will be at a lower energy state than others. ligands that have the ability to cause this splitting are called strong field ligands, cnâ’ is an example of these. if this splitting in the d orbitals is great enough electrons will fill low lying orbitals, pairing with other electrons in a given orbital, before filling higher energy orbitals. in question 7 we had fe2+, furthermore we found that there were a certain number (non-zero) of unpaired electrons. consider now fe(cn)6 4â’: here we also have fe2+, but in this case all the electrons are paired, yielding a diamagnetic species. how can you explain this?