My son and his 11 year old buddies have a lot of energy and love action so a science party seemed the best way to keep them busy and in control. The invitations were made on the computer with an atom picture on the front. No fancy wording - you have to be careful with this age not to be gimicky. I didn't do any decorations, but instead saved the money for the experiments and equipment. Before the party I ordered baby soda bottles/test tubes, a test tube rack, and safety goggles and plastic beakers for each child through Steve Spangler Science. I also ordered disposable lab coats from disposablegarments.com.  I got 2 gallon ziploc bags and wrote the child's name and the words Lab Equipment and Experiments" then added the lab coat goggles a pack of Mentos and an Alkaselter tablet. All the other equipment I put together by experiment in plastic bins. I needed four plastic table cloths a big dishpan for water for handwashing  and lots of old towels. I also made a lightbulb pinata using a balloon and part of a toilet tissue tube for the bottom. I covered it with several layers of paper mache leaving the bottom open painted it yellow then wrapped duct tape around the tube after I put the candy in.  We had a pizza dinner as soon as the kids arrived then the fun began.  The first activity was the Mentos and soda experiment. Everyone had to carry their own bottle outside where the next several messy activities took place.  Last year we did Diet Cola but recently I saw it done with 7-Up so I bought bottles of the store brand diet lemon lime soda for half the price of the brand name and each child got their own bottle. I told them they didn't necessarily have to wear their lab coat and goggles for this one but it turned out to be a good idea as some got silly and tried to drink it as it came out and the lab coats were water resistant (and one kid had his face all drenched so I was glad he was wearing the goggles.) It's hard to find things kids this age have never seen but the next two were new to them and enthralling. Elephant's Toothpaste is a cool concoction of peroxide and yeast and dish soap.  Then we made Non-Newtonian Glop with corn starch water and food coloring.  They got so carried away they went home with a rainbow on their hands. After that we made GAK (the only thing not from Steve Spangler) in which we used Neon food coloring.  We used the plastic beakers to measure out the right amounts of glue water and borax mixture. I gave them small plastic containers to take that home in but repossessed the Glop.  While they made the GAK I bagged up the Glop and took the garden hose to the pans from the first two experiments. By now I was super glad for the lab coats because they were getting really messy but having a ball.  Then we did the pinata and they put their candy in their experiment bags.  We finally took a break and went inside for some ice cream cake.  I found these neat candles at Safeway that are joined together by a wax paper strip so when you light one they all instantly light.  They all thought that was cool.  Next we did some inside experiments since it was dark outside by now.  We used the test tubes in the rack and red cabbage juice to see the effects of acids and bases.  Then we did the fluid stacking experiment and they made lava lamps with test tubes oil water food coloring and the Alkaselter tablets.  We also put Ivory soap bars in the microwave. After the first one a child asked what would happen if we put the second in with the wrapper still on so always open to trying new things we did and I think it turned out even better. When cool I put the remaining soap in a ziploc bag to use the next time I want to make soap balls  (snowballs).  The party was three hours and the timing was perfect - the parents arrived just as we were finishing up.  The kids were so excited to show their parents and tell them what they did (I'm sure the ones who are neatniks aren't thrilled with  me right now - ha ha!)  Each kid took home their lab bags as goody bags with their goggles lab coat their lava lamp a second Alkaselter tablet to show it off and their GAK. I meant to give them their beaker but forgot.  It was a crazy messy party but it was FUN!!! "