Below are listed a number of science project ideas and activities for students, grades K-12. Each of them has a short description and instruction. You will add the hypothesis and determine your methods of testing and control. Some activities require help from an adult. Check first with your teacher or parent before doing a project. Have fun and remember to include EVMWD in your bibliography.

Science Project Related Links

Science Fair Center

Water Center

Project Ideas:

Floating & Sinking

Why do heavy things like soap float but small objects sink in the water? It depends upon how much water an object pushes out of the way or displaces.

• Small ball of clay
• 4-5 marbles
• A clear container to hold water

Drop the marbles into the water. They sink to the bottom. Now drop the ball of clay into the water. The clay also sinks. Neither the marbles nor the ball pushes much water out of the way. Remove the marbles and the clay from the water. Shape the clay into a boat. Add the cargo of marbles. The boat sinks a little on the top of the water, but it floats. The boat is now larger than the ball, so it pushes more water out of the way. It receives a strong upward push from the water underneath. The same concept is used for large boats. Variation: Try other objects. Experiment with the water at different temperatures.

• Tall, clear container
• Syrup
• Cooking oil
• Water
• Cork
• Grape
• Plastic building block

Pour the syrup into the container. Pour in the same amount of oil. It floats on the syrup. Add the same amount of cold water. The water will sink through the oil and float on the syrup. Pour all slowly. Now put in the cork, plastic block, and the grape. The objects float at different levels because they have different densities. This demonstration shows how oil that spills from tankers on the ocean floats because oil is lighter or less dense than ocean water. That is why much of the oil is washed onto beaches. Variation: Try other liquids and objects. Heat one or more of the liquids to a different temperature.

Water Volcano

Did you know that hot water floats on top of cold water? You can see this for yourself by making a volcano erupt under water.

• Glass bowl or tank
• Water
• Food Coloring
• Small bottle with cap

Pour cold water into the tank until it is about ¾ full. Fill the small bottle with hot tap water. Add a few drops of food coloring to the bottle with the hot water. Screw the cap back on the bottle and shake it well. Place the bottle on the bottom of the glass bowl and unscrew the cap. The hot water from the bottle is lighter or less dense than the cold, so it shoots to the top of the tank. The colored hot water forms a layer on top of the cold water. As it cools the colored water mixes with the cold water. Variation: Try reversing the temperatures to see what happens.

Deep Water Diver

How do submarines dive and return to the surface?
You can make your own toy diver and watch it sink and rise in the same
way a submarine dives and surfaces in the sea.

• Plastic pen top
• Glass of water
• Modeling clay
• Clear plastic bottle

Stick a small piece of clay onto the end of the pen clip. This is the diver. Put the diver into a glass of water. Remove or add modeling clay until the diver floats upright. Fill the bottle with water and put the diver in then screw on the top tightly. Squeeze the bottle very hard. The diver sinks to the bottom. Let go of the bottle. Now the diver rises to the top again. Submarines that explore the ocean contain special tanks that are flooded with water to make them dive. Pumping air into the tanks that are flooded with water makes them rise.

• Saucer or dish
• Water
• Glass Bowl
• Pen
• Small glass

Ice Needs Space

See how water grows or expands when it freezes. Nothing can stop it from taking up more space. Ice can even burst metal pipes.

• Water
• Foil
• Funnel
• Small, thick glass or plastic bottle

Using the funnel, completely fill the small bottle with water. Cover the bottle loosely with foil. Put it in the freezer and leave it to freeze solid. As the ice forms, it pushes up the foil. Be careful, the glass may break. Protecting pipes in very cold weather is important. If they freeze, they can break. Insulation on the pipes prevents freezing. Variations: Add salt or another spice to the water to see if it effects the results. Make the plain water your control, then add salt or sugar to other containers to she what, if anything happens. Try filling the water to ½ or ¾ to see if there is any variation in the height of the ice formation, be sure to mark a line on the bottle to where you filled it with the liquid.

• Two jars
• Foil
• Marker Pen

Fill the jars about half full of water. Check that the water level is the same in both and mark that level on the outside of the jar. Make a foil cover for one of the jars. Leave both jars in a warm place for a few days (not the oven). Check the water levels again. Which jar has less water in it? The heat makes the water evaporate in both jars. The foil cover stops the water vapor from escaping into the air so the water level remains higher in that jar. Variation: Add an extra jar and add ice to that one, keeping the water level the same. See if there is any difference in the third jar. Another jar could have salt added.

• Clay pot
• Water
• Small rock to cover the hole on the bottom of the pot
• Dish to go under the pot
• Small item to cool

Soak the pot overnight in water. Put your cooling item under the pot on top of a dish (not paper) and place a rock on the top to cover the hole in the pot. Measure the temperature once an hour for several hours. Variation: Try cooling different items, a can of soda, glass of water, even a couple of ice cubes. Try adding water to the dish under the pot, so the water cools the pot longer.

Rain Gauge

Do you like the rain. Do you ever wonder if the amount of rain that falls in your area is the same amount as the weather person reports? You can measure the rain at your school or at home.

• 2-liter plastic bottle
• Sissors
• Foil

Cut off the top of the bottle (about 5 inches down). Use a ruler to mark an inches scale from the bottom of the bottle up. You may want to mark the ¼, ½ and ¾ inches also so you can have an accurate reading. Set your bottle in an open space being careful not to place it too close to a building or under a tree. Take the top part of the bottle, remove the bottle cap and turn it upside down, placing it into the bottle bottom. This will act as a funnel to catch water so you can tell how much has fallen.

This shows you how to make water defy the law of gravity and flow upward.

• 2 large bowls
• Plastic Tubing

Place one empty bowl on a surface that is lower than another bowl of the same size. Books can be used to elevate the higher bowl. Fill the higher bowl with water (don't fill it too much or it might spill on the books). Put a finger over the one end of the plastic tube and till it with water. Put the end with your finger under the surface of the water in the higher bowl and place the other end in the empty bowl. When you take your finger away, you should see the water flow up the tube, out of the higher bowl and down into the other bowl. The tube forms a siphon, which works because air presses on the surface of the water in the higher bowl and forces water up the tube.

Float the Needle

Can you make metal float on water?

• A clean bowl
• A fork
• A needle

Fill the bowl with fresh water. Rest the needle across the end of the fork and gently lower it onto the top of the water. If you are careful, the needle will float as you take the fork away. Tension on the top of the water supports the needle and stops it from sinking. Variations: Try a small piece of foil instead of the needle. Try other objects that you think may work.

Keep the Water Out

Is your handkerchief waterproof?

• Jar
• Water
• Handkerchief
• Rubberband

Fill a jar with water and soak your handkerchief. Stretch the handkerchief across the mouth of the jar and hold it in place with a rubber band. Turn the jar upside down. Does the water pour out? The handkerchief is made of fibers of cloth with tiny holes. Surface tension acts like a skin and stops water pushing down through the holes. Umbrellas stop water the same way. Variations: Try another liquid instead of water. Be sure to use a plate underneath or do this in a sink or outside so you don't spill.

Stretching the Skin

What happens when the pull of the water's surface tension is weakened?
How stretchy is water's skin?

• Large clean plate
• Water
• Talcum powder
• Soap

Fill the plate with water and wait until the surface is smooth and still. Then sprinkle talcum powder over the surface. Wet one finger and rub it over a piece of soap. Then dip your finger at one side of the plate. All the talcum will be drawn to the other side of the plate. Soap weakens the pull of surface tension in the water around your finger. The pull from the opposite side of the plate is stronger and the talcum powder is drawn over there. Variations: Try adding salt or sugar to the water first. Try dipping your finger in oil instead of soap.

• Mothballs (poisonous, be careful to wash your hands after handling)
• Jar
• Vinegar
• Baking soda

Fill the glass jar with water. Stir in about 1/3-cup vinegar and two teaspoons of baking soda. Stir slowly and carefully so the mixture does not froth up too much. Drop a few mothballs into the fizzy liquid. At first they will sink to the bottom but after a little while each one will rise to the surface again. But they will not stay there. They will keep sinking to the bottom and bouncing up again for several hours. If you look carefully at the mothballs, you will see that they collect bubbles when they are on the bottom. The bubbles escape into the air and the mothballs become too heavy for the few remaining bubbles to support them - so they sink again. Hint, if the mothballs are too smooth, makes the surface rough by sanding them with a little sandpaper. Variations: Try other items, see if you can find something else that has a similar reaction to the carbonation.