Mixing up the Water Column
Materials (for each group of 3/4 students):
- 2 identical wide-mouth jars (20 oz. size work well)
- 2 different food colorings in dropper-type squeeze bottles
- tap water
- 30 oz. cold water, prechilled in refrigerator
- index card slightly larger than the jar mouth
- safety goggles
- Activity 1.4.3 Student Worksheet
Read through steps 1-4 and predict what will happen. Write it down.
- Half fill one of the jars with the hottest water the faucet will provide.
Be careful not to scald yourself!
- Half fill the other jar with the chilled water.
- Allow the water in both jars to settle completely for a minute or so.
- Take one of each of the fool-coloring squeeze bottles in each hand
and carefully -- at the same time -- squeeze
one drop of color into each jar.
- Observe and record what happens.
Illustrate Part A below:
Read through steps 1-6 and predict what will happen. Write
- Completely fill one jar with hot tap water and the second jar with
cold water from the refrigerator.
- Add several drops of different colors of food coloring to each jar.
- Place the index card over the mouth of the jar filled with hot
- Holding the card firmly in place, quickly invert the jar of hot water
and place it over the mouth of the jar filled with cold water.
- While holding the jars in place, carefully remove the card and observe
* Is this what you expected?
- Now turn the jars over so that the hot water is on the bottom. What
happens now? Record the results of the last two steps.
Illustrate Part B below:
Student Worksheet #1.4.3