We have spent a lot of time exploring with water. You have observed the "stickiness" of water. You noted how water drops "like each other" and attract and pull at each other and how water seems to hold together like magnets do or like things attracted together by static electricity.
You have probably talked about the word "surface tension". These activities below explore how dish soap/dish detergent can change the surface of the water and make boats that will move across the water's surface. Give them a try and watch them go!
Below are some fun videos about soap boats. Try some of these at home, but make sure you have an adult assistant who can help you cut things out and gather the materials.
Cereal boxes are pretty much the best paper for these boasts. You can also come and get some index cards from me if you don't have a cereal box at home.
Soap Powered Boat #1 - this site has a pattern that you can use for your first try.
Soap Powered Boat #2 This one uses a bread bag closer for a boat! I have lots in my classroom if you need one.
Once you get a boat that works well, try experimenting! Remember though, you should only change one thing at a time.
Do they all behave the same? Share some of your results with me or your class!