Here are some fun, sometimes exciting, sometimes messy projects you can try in your kitchen. They generally have some scientific aspect to them, but only if you put the effort in to talk up the science while the kids are playing, but that's what homeschooling is all about.
skeeter
Crystals
Here's how to make some neato crystals
Mix 1 part epsom salt to 1 part water
Add a dash of food coloring
Bring to a boil
Pour into shallow containers (like jar lids)
Wait for a day or so...
Enjoy neato crystals
Think about neato crystals
Don't eat neato crystals
Play Dough
Here's how to make your own "Modeling Compound"
1/2 c salt
1 c flour
1 T cream of tartar
1 T oil
1 c water
Put in a pot and heat slowly, stirring it until it is a ball.