Chemistry, chemistry, chemistry

I have been teaching my unit since April 1st. I assigned homework every night (except the night before the test). Usually there is time at the end of the class to begin working on homework so I can answer any questions that arise. I didn't make it through my entire unit since we got stuck on Lewis structures, VSEPR theory, and molecular geometry. My school supervisor agreed that we shouldn't force ion, ionic compounds, metals and metallic bonding down their throats the day before the exam. We did start a lab about metals, but its an investigation into the properties of three metals, and using these properties to successfully separate a mixture, then to successfully identify the composition of an unknown mixture. The kids didn't all get finished with the lab - I find that many of the kids have to prompted for each step of the lab - I know these students can read but apparently they can't follow directions. I went over in detail what they would be doing by demonstrating the lab, and I wrote the steps as a graphic organizer on the board.
Lewis structures are nonlinguistic representations of elements and compounds. The students seemed to understand (finally!) but many of the can't remember how to determine bonding configuration, which is essential to drawing Lewis structures. I think that its more that the kids don't want to remember, I know that they are bright and that they can do this stuff, but they just won't do it. When I ask questions in class I require an answer, even if we have to wait for someone to look it up. I do accept "we have no idea" but that does frustrate me, because I know that they have the information and the prior instruction needed to answer the questions. I used graphic representations on the dryerase board for students to be able to relate the information. I emphasized the importance of taking good notes, and told them I am going to grade their notes and homework. There is no reason for anyone's homework to be incomplete, because we discussed it everyday, so students could see where they made mistakes and we could talk about things that they don't understand. I gave an exam on Thursday and I let them use their notes and homework and I'm amazed at how poorly they did. The best scores so far are from the students who asked the most questions in class. I didn't think the test was that hard, and I give partial credit and accept nonlinguistic representations for answers to questions that really want a written answer.
Tomlison/McTighe say that "instruction is both planned and improvisational" (p.89) and that perfectly describes my teaching experience.