Liquids and Solids

Grade 2 Physical Sciences

Outcome: Assess methods of combining liquids and solids to make useful materials and the impact liquids and solids have on self, society and the environment.

Indicator:  Assess the ways we use our knowledge of solids and liquids to maintain a clean and healthy environment. (eg. Filtering water, sorting solids for recycling, cleaning up a kitchen spill, washing dishes, cleaning paint brushes, using hand cleaners, wearing a paint smock).

Objectives

Students will become aware of where the liquids in our houses and streets go (plumbing and sewer systems).

Students will learn why certain liquids cannot be disposed of through that system, as they would contaminate our water and natural environment.

Materials :

• Supplies to make one or more simple water mazes:
• glass or Pyrex pie plate or cake pan (base for the maze)
• Play clay (use thin rolls of the clay stuck on the surface to make the “maze” for water to run).  This maze will be used to represent the storm sewer system and ground runoff, so it needn’t be complicated. The maze should have a starting point and a pool at the end representing a river or lake.
• Water
• Powdered tempera paint in a colour that contrasts the play clay.
• An overhead projector for visibility of maze, if you choose to make just one maze.
• Can of paint (or a photo of one)
• Motor oil - 1 litre container (or a photo of one)

Instructional Procedures:

1. Explain to students the basics of plumbing and sewers. Waste water from our houses (like baths and flushing the toilet) goes from the pipes in our houses to water treatment plants where it is purified to be used in our houses again.  Rain water, and any other water that runs onto the street (like the water from washing vehicles, or excess water from watering lawns) either goes into storm drains (in urban areas) or into the soil (in rural areas).  Storm drains go to rivers and lakes and the water is not treated or filtered.
2. Show students the water maze and explain that it represents the path that rain water and other liquid run-off follows on its way to rivers and lakes through a storm drain.
3. Add a few drops of water into the start of the maze and tip the maze to run the water to the end – the longer or more complicated the maze, the more water you will need to add.  Explain that when the water is clean, such as when it is rain water or run-off from our lawns, there is no environmental damage done, although the run-off from our lawns is wasteful.
4. Show students the can of paint and the litre of oil. Ask them if they know what they are used for. Explain that they are not harmful when used for their intended purpose. Ask students what we should do with these liquids once we are done with them. Why would it be a bad idea to pour liquids like these down the drain with our water?
5. Going back to the water maze, add some powdered tempera paint to the water, but do not mix the paint in.  You want it to remain mostly powder.  Explain that the powdered paint represents another liquid going down the drain with the water. It could be oil or paint (dumped down storm drains), ice salt (from roads) as well as garbage and other contaminants that are washed down storm drains. Have the students observe the water and tempera paint as you guide them through the maze by tipping the pan.  They should note that most of the “contaminant” floats with the water and collects in the river/lake at the end.
6. Show the students the one-litre container.  Explain to them that one litre of oil can contaminate 1 million litres of water.  A very small amount can “dirty” a very large amount of water. You may choose to show them the Mr. OilDrop video found at http://www.usedoilrecycling.com/en/sk/ecoschool.
7. If products like oil or paint get into our water, it is dangerous for animals, plants and people (See Teacher Information Sheet for details).
8. How can we prevent these types of materials from getting into our rivers and lakes?  Instead of pouring them into a drain, oil and paint can and should be recycled.  Paint that is no longer needed or useful can be dropped off at any SARCAN location. Used oil and filter drop-offs can be found at http://www.usedoilrecycling.com.
9. Have students make pamphlets describing the dangers of oil and paint in the water system and how to prevent the contamination. Let them take the pamphlets home to share with their parents.

 Printable PDF version including teacher reference sheet

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