Build Your own Water Filter

Since water is a rare commodity in space, astronauts on the International Space Station recycle all the
water they use. This includes sweat, shower and shaving water, even urine! This wastewater is purified and
then recycled for drinking and other uses.

To understand how water filtration works, try this activity. (Note: This experiment only demonstrates a type
of water filtration. The experiment will not purify water for drinking purposes.)

Materials

• Clear plastic pop bottle (2 litres)
• Aquarium gravel
• Sand
• Aquarium charcoal (activated)
• Cheesecloth (a nylon stocking can also be used)
• Muddy water
• Rubber bands

What to do

1. Cut the bottom off the pop bottle. Cover the mouth of the bottle with several layers of cheesecloth and secure the cloth with a rubber band. Suspend the bottle upside down with its mouth over a container to catch the filtered water.
2. Using the hole cut in the bottom, fill the bottle with charcoal to a depth of 5-8 cm.
3. Place 8 - 10 cm of sand on top of the charcoal.
4. Add another 5 - 8 cm of gravel on top of the sand.
5. Stir the muddy water and pour it into the filter. Watch closely as the water seeps down through the three filtering layers of gravel, sand, and charcoal.

Discussion

• What happened to the water while it passed through the different layers of the filter?
• Compare the muddy water to the filtered water. Is there a difference?
• Would it make a difference if one of the layers had been left out?

Luminous Water

Water and glass can act as obstacles, causing light to deviate or change direction. This experiment is a good way to demonstrate what happens.

Materials

• Scissors
• Clear plastic bottle
• Water
• Flat dish
• Small flashlight

What to do

1. Use the scissors to poke a small hole in the bottom third on the side of the bottle. With your finger on the hole, fill the bottle with water. Place the bottle on the dish and turn off the lights in the room.
2. Let the water trickle out of the hole into the dish. Shine the beam of the flashlight around the bottle, level with the hole. If the beam is properly positioned, the water trickling from the bottle should become luminous. Even the water in the dish should emit light.

The Colour Spectrum

Light may look transparent, but it actually consists of many colours - red, orange, yellow, green, blue, indigo and purple. These different colours are called the Colour Spectrum and were first understood by Isaac Newton. Here's an experiment that demonstrates the colour spectrum.
Materials

• Black paper
• Scissors
• Tape
• Flashlight
• Clear plastic box (a Tupperware container works)
• Mirror
• Thick white paper

What to do

1. Make a small notch in the black paper and tape it to the glass part of the flashlight.
2. Pour water into the box to the halfway point. Stand the mirror up in the water against one side of the box.
3. Turn off the lights and focus the beam of the flashlight on the part of the mirror that's submerged.
4. Hold a sheet of white paper so that it reflects the light. The colours of the rainbow will appear on the sheet of paper.

Locating Magnetic North

The Earth is like a great big magnet that forces all the other magnets to point to magnetic north at the top of the world. Here are a couple of experiments that involve locating magnetic north.

1. Observing Shadows
Go outside on a sunny day, around noon, and observe which way your shadow is pointing.

Shadows point northward because Canada is located in the Northern Hemisphere. If we lived in the Southern Hemisphere, our shadows would point southward.

2. Making a Compass

Step A

Materials

• Bar-shaped magnet
• Tape
• Small plastic container
• Bowl
• Water
• Stick-on labels

What to do

1. Tape the magnet flat in the middle of the small plastic container.
2. Fill the bowl with water and float the container in the bowl.
3. Once the container stops moving, mark the edge of the bowl with two labels opposite either end of the magnet - one for north and one for south.

Proceed to step B to see which is north.

Step B

Materials

• Piece of cardboard
• Pen
• Scissors

What to do

1. Cut out a circle of cardboard the same size as the opening of the small plastic container.
2. Draw a cross on the cardboard. At each of the four points, moving clockwise, write the first letter of the cardinal points - N (north), E (east), S (south), W (west).
3. Place the cardboard on the container so that the N is opposite one of the labels. As you turn the container slightly, you can see that the magnet keeps turning back to face north. Place the N at that mark. Once the magnet stops moving, the compass will show the cardinal points.

Mystery Phrase

How to play: In the following table, each symbol represents two letters. Use the following codes to find the mystery phrase.

Jumble Words

Unscramble the following words and, using the highlighted letters, find the Secret Word!

Word Searches

Take a break and relax with these transport-related word searches to learn about transport in Canada - by Air, Rail, Water and Road!