For my son Payton's 9th birthday, we had a mad scientist party with 12 kids.  It was great. I sent out inviations on laser paper that were outlined with beekers, test tubes, lab jacket, rock candy and more. Printed in the middle was "Oooze on over to Payton's for a Weird Science Party!!" It listed what, where, when and asked parents to send kids in an old shirt "Cause things just might get MESSY!!"  I set up tables for each experiment.  At the first table, I gave each kid a box of molding clay with 4 colors and told them to make a volcano.  (clay was from the dollar store)  As each child finished thier volcano, I gave them a paper cupcake holder with baking soda in it to add to the middle of the volcano.  Then they added a drop or two of dish soap, a couple drops of red food coloring and the secret ingredient of VINEGAR!! The eruption had begun, things were just getting off to a bubbly start and the kids were going crazy already.  They kept adding more baking soda, more vinegar, more food coloring!!    Next we moved on to alka selzer rockets. These were a real BLAST!!  One film canister, an alka selzer tablet, little warm water and WOW, things were starting to blast off!! The kids were so amazed that we spent a half hour doing just this. Which gave me time to prep for the next table. They were really loving this one. We moved on to water bottles, balloons, vinegar and baking soda. After adding the mix to the bottle, we raced to get the balloons on top and see who's blew up the most.  The kids were swirling the bottles to get more of a reaction.  They were amazed at how well this worked.  For our finale, I set out some magic sand/water tray's, while I again set up our next station.   Last but not least we made slime or for them "SNOT". By using elmers glue, borax soap, water and a drop or two of green food coloring, we had instant nose blowing laughter.  The kids were having a great time sliming each other.  They all got a plastic egg to put there slime in to take home.  It hold up rather well, almost like silly putty.   For party favors, I gave magnets, microscopes, balloons, alka selzer rocket material, blow up bubble balloons, pop rocks that came with test tubes, a scientist note pad and pencil, some candy, a empty plastic test tube and one full of small candies (test tubes were from a paint ball store) and a home made book of experiments for them to try at home with thier parents. Payton's cake was a volcano with Ooozing Lava, some tree's, a dinosaur, little lake and candy pebbles. It was a real hit and the kids at school are still talking about how much fun they had.  This was by far the most fun I have had in a long time at a party and my son loved it!! What was even better was the parents were full of excitement as they told me how much fun thier kids had. Then another person who didn't know the kids at my party was telling me about this science party her friends son attended and how excited it had gotten him!!