Distribution of Earth's Water
Science Experiment to Calculate the Percentage of Water on Earth
Earth's water distribution science experiment to illustrate percentage of water available for human use.
Conservation and protection of the earth's fresh water is essential for human survival. Luckily, in 1970 Earth Day was created to educate and bring forth issues about our earth resources such as water.
Approximately, 70% of our earth is covered by water, but unfortunately only about 1% is safe for human consumption. Much of our water is located in our oceans, and only a small percentage is fresh water. Of the fresh water, much of it is inaccessible because it is locked in icecaps and glaciers. Earth week, earth day, or earth month are great opportunities to discuss the importance of our fresh water resource and how to make a difference one student at a time.
Best way to engage a student in learning about an Earth Day issue is to give them a WOW presentation. Start the presentation by having students physically witness the amount of fresh water available for human and animal consumption with a group experiment.
Earth's Water Distribution Experiment
Divide the class into groups of four or five to allow all students to examine the experiment up close an personal.
Each group needs 3 one-liter bottles, measuring cup, and a 10ml dropper, funnel and a bucket of water.
Teacher asks students the location of water on earth. Students will begin brainstorming ideas such as oceans, seas, lakes, rivers, rain, and more. Teacher will place the ideas into 3 different columns. He will not have labeled the 3 columns, but he will order them himself according to the three types of water found on Earth: salt water, fresh water and locked water.
Teacher will continue to write the students ideas until they are exhausted. After the ideas are in their columns the teacher will have the groups to take a few minutes to decide on the name for each column. If one column is blank, the students will decide on the names for two columns.
Next, the teacher will take their ideas and will label the columns. The columns are Salt Water (Oceans, Seas), Locked Water (Ice Caps, Glaciers), and Fresh Water (Lakes, Rivers). Often students will forget about the locked water because it is in a different state. Teacher can give a mini lesson on the locked water.
After students are aware of the earth's water distributors, the teacher will ask each group to decide on a percentage for each column. Teacher may choose to have students look at an atlas to get an idea of the vastness of the oceans. Teacher will write the groups predictions under each column and make no comment about the number being too low or high.
Teacher will ask students to fill their measuring cup with 975 ml (33 oz) of the water from the bucket. Teacher will ask students to predict if the water represents the salt water, locked water or fresh water. Students will pour the water into a one-liter bottle using the funnel. Students will label the water salt water and underneath write oceans and 97%. Approximately, 97% of our world is found in our oceans.
Teacher will ask students to fill their measuring cup with 24 ml ( 1 oz) of water from the bucket and again ask students to predict if the water represents fresh water or locked water. Students will pour the water with the funnel into a one-liter bottle and label it locked water and underneath write glaciers and ice caps and 2.5%. Approximately 2.5% of our water is inaccessible to humans. Teacher will ask students how much water do they have left to represent fresh water.
Students will use the 10 ml dropper to gather 1 ml (.05 oz) of water and place the amount in the last one-liter bottle and label it fresh water and underneath write lakes and rivers and 0.5%. Less than 0.5% of fresh water is available on earth.
Earth Day Lesson Follow-up
After the experiment have students write in their journal their thoughts and feelings about the distribution of water on earth. Tell students to write freely about the experiment and what they learned today about earth's water resources.
Water is a valuable resource that is taken for granted by first world countries' inhabitants because of easy access and inexpensive costs. After the experiments, students will have a true representation of the amount of water truly available to us and is a great introduction to water pollution, water conservation, and Earth Day.
