SCSP

( indicates material is included in the kit)

• FLOATING AND SINKING

Why do some Crayons (different colors) float and some do not?

Supplies:	graduated cylinder
	sensitive scale
	basic eight crayons (which have never been used)

Try to float different color crayons on water.  Some float, some sink.  
Use a scale to weigh each crayon and measure the water displaced by each crayon with the graduated cylinder.  Make a chart or graph of the results.

• FLOATING PIN + DETERGENT

Can you make a pin/paperclip float on water?  (Hint: the clip has to be clean. dry and very flat

Add detergent: why does the pin sink?

Supplies:	pin/paperclip
	detergent
	container of water

Ideas: Can be used as an assessment, possibly use on the overhead

Application: Water bugs and larvae found in nature posses the same qualities

Option: Add more paper clips to the water, paper clips will come together because the outside water force is greater than the force generated by the small amount of water between the clips.  This pushes the clips together.

• BUOYANCY EXPERIMENT

Supplies:	eyedropper
	clay
	two liter bottle

Preparation: To prepare the "diver," obtain a 1-hole stopper.  Insert a small piece of tubing.  Put some clay on the bottom to seal the air in and keep the stopper "Upright."  Put a little water in it.  (Every stopper is different and the teacher needs to spend 2 or 3 minutes experimenting to get the right balance.)  Once it's done, put the diver in the bottle filled 3/4 with water. Screw on the top, tightly. Ask students for predictions of what will happen when you squeeze the bottle. Then squeeze, and the diver goes down; release and the diver rises.  Let the kids figure out why.

Explanation: Increasing air pressure when you squeeze the bottle increases the amount of water inside the diver.  It gets heavier (water is denser than air), so it goes down.

Enrichment Challenge:

1. Try to obtain neutral buoyancy such as can be seen in submarines and fish.

2. Find an aquatic animal that has an air bladder and an aquatic animal that doesn’t.  Explain how each stays underwater.

• TOOTHPICK STAR

Supplies:	five bent toothpicks in the shape of a star
	eye dropper
	pie plate

The toothpicks should be bent in half at the midpoint, but not all the way through.  Form toothpicks into a star by placing with the open ends touching at the outside with the bent edges toward the center, like a starfish.  Drop water into the center of the star.  When the water is dropped, the star opens.  A pie plate works well, as does any slick surface. Leftover laminating film works fine, too. The toothpicks just need a low-resistance surface. Explanation: Water pressure pushes toothpicks apart

• WATER PRESSURE

Supplies:

2-liter bottle with two or three holes (one towards the top, optional one in the middle, and one near the top).  Younger children do better with just 2 holes to watch. Optional: pan (see below)

There are two ways to do this.  One is to tape the holes shut, and have 3 children remove the 3 pieces of tape simultaneously,  Or, 3 children can each put a finger over one of the holes while you fill the bottle. They have to pull their fingers away all at the same time.  The water spurts farthest from the bottom hole, least far from the top hole.  This illustrates how the pressure is different at the bottom than the top, and gives a visible display of pressure.  Make a point of noting that it is the weight of water on top of the hole that causes the pressure. Notes: The water runs out very quickly.  It really is done best outside (on a warm day), or at a sink if you have one.  Or, obtain a large, deep pan to catch the water.  Even a trash can will work.  Experiment with the placement of the holes.  Make sure that (1) the top hole is not so close to the top that the water runs past it before anyone has a chance to see, and (2) the bottom hole is far enough from the bottom so that water running out of it is visible.