HIJKLMNO….a closer look at H2O

Liquids and solids interact in different ways.

Inquiry Skills Used

This is a research activity using various problem-solving processes and observations to assess the outcome of the experiment.

Safety Considerations

Even though this is an incredibly safe activity, it provides a great opportunity to model safety practices, such as using our senses safely when observing, and working carefully.  Students should be told not to put ice cubes in their mouths.

Background

Many children can identify that water exists in 3 states within our natural environment.  Understanding that it is the very same water that undergoes changes of state presents far more of a challenge to children in grade 2.  The following experiments are simple yet effective in helping children understand changes in state.

What You Need

• Ice cube trays
• Freezer
• Food colouring
• Water
• Empty, clean can (without label)
• Transparent or translucent pitcher
• Glass

Part 1

1. Begin with a discussion about what colour the water is (guide students to use the words clear and colourless).
2. Have the students make predictions and observe what happens when drops of food colouring are added to a pitcher of water.  Will the water still be clear and colourless?  Complete this and observe.
3. Again, have them predict what will happen when the same water is poured into a glass.  Will the colour travel with the water?  What shape will it be?  Complete this and observe.
4. Next, fill some ice cube trays with coloured water.  Have students predict what will happen when the trays are placed in the staff room freezer overnight (if cold enough, place them outside).  What colour/shape will the ice cubes be?  Freeze them overnight and observe them the next day.  Ask students, why did they freeze?

Part 2

1. Is there water in the air around us?
2. Fill the can up with the coloured ice cubes and have students closely observe the outer side of the can.  The water that condenses will not be coloured which indicates that it came from a different source than within the can. (It condensed from the air.)  What temperature is the outside of the can?
3. Finally, set up a saucer with a small amount of water in it.  It should be placed in a warm location, if possible, and left to stand overnight.  Next day, observe the evaporation that took place.  Where did the water go?  What temperature was the air surrounding the plate?

Where to Go from Here?

Many other experiments can be performed with water.  Water is by far one of the safest chemicals children can use for experimenting.

Investigations with snow and water can be used to introduce controlling variables.

Go outside on a very cold day and use bubble wands and bubble soap to blow bubbles.  Note the water vapour cloud left when the bubble bursts.

Where can we find ice outside?  Where did the ice come from? Where does the precipitation come from (lakes, rivers, streams, puddles, rain, clouds)?  Students can record what they have seen using pictures or diagrams.

The food colouring could be like pollution in the water.  When the water freezes, does the food colouring stay in the water?  When the water is evaporated from the container, does the food colouring remain in the container or go into the air with the water vapour?

Cross Curricular Connections

There is a significant opportunity to consider this as a data management research activity, as well as  informational writing and media literacy by looking at and discussing other types of pamphlets and information sources, such as web sites that target specific audiences.

Math

• Measurement – use thermometers to record the temperature of the ice water.
• Data Management – Chart the temperatures at half-hour intervals during the school day.