Introducing the Scientific Method
Teach the scientific method to ELLs byconducting science experiments in your ESL class. This will introduce your students to the necessary science vocabulary and teach them how to make educated guesses. This is a difficult concept for some ELLs who have been schooled to only give correct responses.
Here are the benefits to teaching science experiments in ESL class:
development of science vocabulary
hands-on learning
reinforcement of sequencing
development of higher level thinking skills
authentic reasons to interact with classmates
development of co-operative learning strategies
forming hypotheses
accessing prior knowledge
finding a real audience for work
development of research and computer skills
development of oral language - managable chunks of learning
Experiment # 1: How to Tell If An Egg is Cooked1. Materials: hard-boiled eggs, raw eggs
2. Vocabulary: hard-boiled , raw, experiment, hypothesis, materials, procedure, results, conclusion
3. Before this lesson is taught, students need to know the vocabulary “cooked” and “raw.” This is best demonstrated by showing them the inside of a hard-boiled egg and of a raw egg. More advanced students can talk about the way the inside looks, smells, and feels in response to questions such as, “Do the cooked and raw eggs smell the same? Do the whites of cooked and raw eggs look the same? feel the same? How are the yolks different?”
4. Have students examine a cooked egg and a raw egg which have been marked Egg A and Egg B. Can they tell which egg is cooked and which one is raw without breaking the eggs? Do the two eggs feel different? Do they smell different? Do they look different? If shaken, do the eggs sound different ? What we want to find out during the experiment is called “ the question.” Have the students write the “question” in their science notebooks. (Can we tell a cooked egg from a raw egg without breaking it?)
5. Students then look at the eggs and guess which egg is cooked and which is raw. They write their answers in their science notebooks. This part of the experiment is called the “guess” or the “hypothesis.” Students need to know that it does not need to be correct. The next part of the experiment is the “procedure” or the steps of the experiment. This tells what is done first, second, third, etc.
Spin the egg on its side very fast.
Make it stop by pressing on it with your finger.
Remove your finger quickly.
The students will see that a raw egg will continue to spin.
6. Explain that this is called the “result” or what happens during the experiment.
7.Students then tell why they think the raw egg continues to spin. Accept a simple explanation such as the contents of the raw egg continues to move because it is liquid. A hard-boiled egg could not start spinning again once it is stopped because its contents are solid. Explain to students that this is the “conclusion,” or what we learned during the experiment.
8. Have each student draw a picture of one of the parts of the scientific method. Ask them to label their drawings. They should then sequence their pictures.
Experiment #2: Why Doesn't A Mother Bird Break Her Eggs?This experiment helps young children understand that a mother bird can sit on its eggs without breaking them. Students learn to discuss a scientific process and practice new language patterns.
As we do the experiment, we “think aloud” to model the language.
1. Question: Can six eggs shells hold 3-4 heavy dictionaries?
2. Hypothesis: Students guess “yes” or “no” and their guesses are recorded.
3. Materials: six large eggs, scissors, a cup, 3-4 dictionaries, masking tape. We tell students that the materials are things needed to do the experiment.
4. Procedure:
Crack end off of each egg and empty the yolk in a cup.
Wash shells and let them dry.
Cut edges with scissors and cover them with masking tape.
Arrange eggshells in a square and put one dictionary on top.
5. At this point ask students if they would like to change their guess, while showing them that there are still two dictionaries to put on the eggs. Most students will want to change their guess. We explain that this is what an experiment is: to make a guess about something, To try out something new and to change the guess if you need to.
6. Results: The eggshells do not break.
7. Conclusion: The arc-like shape of the egg helps support the weight of the dictionaries. The shape of the egg is the reason it doesn’t break when a bird sits on it.
Experiment # 3: Can you Make An Egg Bounce?
1. Question: Bounce a ball or other round object for students. Try to find an object that has a low bounce. Ask the question, “Can you make an egg bounce?”
2. Hypothesis: (guess) Students should make a guess and write down their conclusions.
3. Materials: hard-boiled eggs, white vinegar, jar or large cup and water.
4. Procedure:
Soak eggs in white vinegar for 48-72 hours until all of the shell is dissolved.
Take the egg from the vinegar and soak it in water overnight.
Have students lightly drop the egg on a table from two or three feet.
5. Result: The egg does not break. It “bounces.” Do not drop the egg from a distance of more than a few feet or it will break. It bounces just a little.
6. Conclusion: The vinegar removes the shell but leaves the membrane or skin. The water stretches the membrane which is thick and can be shown to students. This allows the egg to “bounce.”
7. Assessment
Ask students to draw and label the steps of the experiment on large index cards. Also have them compare a peeled hard-boiled egg with their bouncing egg. Do they look and feel different? Is there a different smell? Where is the membrane on the hard-boiled egg? This helps students understand why the membrane on the “bouncing” egg is strong.
8. Extension
Students present their bouncing egg experiment to their mainstream classes. They pose the question “ Do you think this egg will bounce?” and then demonstrate their experiment. After they have completed an oral presentation, the index cards will be glued to their poster board and the poster boards can be hung in the hallway for other students in the school to see.
Experiment # 4: Egg in a bottle
1. Question: Can you show how air expands when heated and contracts when cooled? Use this "Egg in the Bottle" experiment to demonstrate.
2. Hypothesis: (guess) Students should make a guess and write down their conclusions.
3. Materials: A hard-boiled egg, a glass juice bottle, piece of paper; matches.
4. Procedure:
Shell a hard-boiled egg.
Light a folded piece of paper with a match and drop it into the bottle.
Put the egg on the opening at the neck of the bottle.
5. Result: When the air contracts the egg is pulled into the bottle.
6. Conclusion: The air expands and the air molecules move apart when the lighted paper is dropped into the bottle. When the air cools, it contracts and the egg is pulled into the bottle.
7. Assessment
Ask students to draw and label the steps of the experiment on large index cards.
8. Extension
1.Students present their "Egg in the Bottle" experiment to their mainstream classes. They pose the question “ Do you think I can fit this egg into the bottle?” and then demonstrate their experiment. After they have completed an oral presentation, the index cards will be glued to their poster board and the poster boards can be hung in the hallway for other students in the school to see.
2. How can students get the egg out of the bottle? Have them wash the burned paper from the inside of the bottle. Turn the bottle upside down and blow very hard. As soon as you have blown enough air into the bottle, the egg will fly out. Get ready to move your face quickly.
t for a while, so that a layer of carbon dioxide forms at the bottom of the tank. Then gently blow soap bubbles over the tank. The bubbles will sink into the tank and then stop, floating in mid- air. (The air in the bubbles is less dense than the purer CO2 at the bottom.) Very cool.
