You will need the following supplies for this experiment:
- Two equally sized jars
- Measuring spoon
- Oil (Vegetable or Olive)
- Measuring cup
- Sticker labels
Follow the steps below to do this experiment:
- Explain to your students how harmful oil spill are to the animals that live in the water where the spill occurred. Show them pictures of some birds or ducks that are covered in oil. Oil spills can kill fish and damage underwater plant life. This experiment will show students if oils spills that occur in salt water are easier or harder to clean up then in fresh water.
- Get out two equally sized jars. This is extremely important so that the experiment is not biased. Your jars will also need secure lids since you are going to be shaking them.
- Use your measuring cup to pour 3/4 cup of water in each jar. The jars must contain equal amounts of water.
- Choose one jar to be your salt water jar and one to be your fresh water jar. Use some sticky labels to write Fresh Water and Salt Water on. Stick one label on each jar.
- Take the jar labeled Salt Water and add 4 tablespoons of salt with your measuring spoon. Stir in the salt.
- Now add 1/4 cup of oil (either vegetable or olive oil will do) to each jar. You can use your measuring cup.
- Place the lids tightly on each jar.
- Shake each jar as if the waves of the ocean were shaking it. It is important that you shake each jar the same amount of time so count each shake you give your first jar. Now shake the second jar the same amount of times.
- Use your watch to document what time it is.
- Watch each jar to see how long the oil takes to settle on the top. Write down on the blackboard Fresh Water and Salt Water. Write under each one what time it was when the oil separated from the water and rested on the top. Which one settled first? Did they settle at the same time? Have the class come to a conclusion as to which type of body of water would be easier to clean up and have them give reasons why.
*Optional step: Repeat the experiment with real salt water from the Ocean and some fresh water from a Lake.