The first is that I effectively have no Science unit.
The second is that I have a very shaky Science knowledge base myself.
Google, oh google, I use you an awful lot.
So I've decided on attempting to teach gravity, potential energy and kinetic energy. I'd have the introductory lesson being about figuring out what students already know about energy with a postbox and any questions they have, and then doing some gravity exercises with dropping objects from great heights. This is going to be during the lessons after lunchtime, nearing hometime, so they're restless at this point and probably not up to doing a great deal of written work (Mondayitis).
Hey, you know what I need? A teacher in my family who knows what the hell I should be doing. I curse you, Flinders University, for providing no support for lesson or unit planning.