At home science experiments - Great cure for snow day boredom! :0)

Parents,

Many students have told me that they have enjoyed doing the at home science experiments.  I thought I would suggest a couple others related to our studies than can be done for extra credit at home.  To receive extra credit, all I need is for the student to show me in some way what was done at home - pictures are great as I like to put them on the class website.  An e-mail or handwritten paper describing what happened is also great.

-Mr. Pransky

Here are several options:

1.  Difficulty:Easy.  Many students enjoyed floating the paper clip in water.  Here's a simple variation of that activity.  Do it again, but this time put a drop of dish soap in the water. This will bind with the water molecules, interfering with the surface tension. The paper clip will sink. You can try floating other things on top of the water also - pepper floats well until you add dish soap. Can you find any other light items that will float?  Take pictures or write an e-mail me of your results.

2.  Difficulty:Easy.  Penny drop #2.  

Remember the penny drop experiment?  Try testing, how many drops of water one penny can hold.  Record your results.  Then add detergent or soap to the water and try it again.  Does hold more, less, or the same with the soapy water 

3. 

Difficulty:Easy.  Penny drop #3.  

Remember the penny drop experiment?  Try comparing how many drops of water one penny can hold on either the heads or the tails side.  Do three tests on each side.  Does one hold more water than the other?

4.  Difficulty:Easy.  Make a boat from a margarine tub. Predict how many pennies it will hold before it sinks.  Test and record your data and prediction!

5.  Difficulty: Medium  

Can water move uphill? Cut a strip of coffee filter paper or a paper towel. Hold the strip so the bottom barely touches the surface of the water. What happens? Build a tower of sugar cubes in a shallow dish, then add a little colored water in the bottom. Watch the result.

6.  Difficulty:Medium  Have you ever wondered why rivers and lakes freeze in the winter, but oceans do not? In this experiment we will see that it is the presence of salt in the ocean that makes it less likely to freeze. 

Materials:

• 1-gallon freezer bag
• 1-quart freezer bag
• crushed ice
• salt
• thermometer

What To Do:

1. Fill the gallon freezer bag half full with crushed ice. Add one cup of salt and seal the bag. Put on some gloves and knead the ice and salt until the ice has completely melted.

2. Use the thermometer to record the temperature of the saltwater mixture. Even though the ice has melted, the temperature should be less than 32°F (0°C).

3. Now put about an ounce of water in the quart freezer bag. Seal the quart bag and then put it in the saltwater mixture in the larger bag. Seal the larger bag also and leave it until the water inside the quart bag freezes.

How did the water freeze when surrounded only by saltwater? The salt broke apart the bonds between the water molecules in the ice, causing it to melt, but the temperature remained below the freezing point for pure water. Salt (and other substances dissolved in water) will always lower the freezing point. This is why water in the ocean rarely freezes.

7.  Difficulty: Hard  

Design an experiment to test this question: "Can hot water freeze faster than cold water?"  You may be surprised at the results.  For an explanation of why this occurs, search online for the "Mpemba Effect."

--
Shane Pransky
Whitehouse Primary
4th Grade