Good science experiments for a group?

GingerSB

I am trying to plan a science experiment for my dd's Sparks meeting. There will be 17 girls ages 5-6.  I wanted each girl to make a lava lamp, but DH thinks it would be a nightmare!  Any opinions or other ideas for a science night? I need to fill about 45 mins of time.

TIA

Materials

• Clean, plastic soda bottle (16 oz size works well)
• Soda bottle cap
• Vegetable oil (the cheaper the better)
• Food coloring 
• Alka-Seltzer tablet 
• Water
• 1. Fill the bottle 3/4 full with vegetable oil.
  2. Fill the rest of the bottle with water (almost to the top but not overflowing).
  3. Add about 10 drops of food coloring. Be sure to make the water fairly dark in color. Notice that the food coloring only colors the water and not the oil. Hmmm...
  4. Divide the Alka-Seltzer tablet into 8 pieces.
  5. Drop one of the tiny pieces of Alka-Seltzer into the oil and water mixture. Watch what happens. When the bubbling stops, add another chunk of Alka-Seltzer. It?s just like a lava lamp!
  6. When you have used up all of the Alka-Seltzer and the bubbling has completely stopped, screw on the soda bottle cap. Tip the bottle back and forth and watch the wave appear. The tiny droplets of liquid join together to make one big lava-like blob.

Ms5586

That sounds like a blast...but maybe too much with that age group.  Will you have any other adult helpers?  I see the kids having trouble pouring the correct amount of veg oil in.

You could have the oil in their bottles ready to go, and have them fill the rest with water.  You could have the alka seltzer tablets ready for them to grab a piece to put in.

I think the kids would absolutely love it, but I don't have any other ideas for you.