The scientific method is one of the most powerful ways to study the world around us. It helps organize ideas and processes for systematic analysis. The steps of the scientific method -- observation/research, hypothesis, prediction, experimentation and conclusion – work as well for second-graders as they do for Nobel laureates. Making orderly notes in a notebook gives the scientist a record to track the experiment and to give other scientists directions for replicating the experiment.
Mixing Oil and Water
This experiment shows how oil and water react together. You’ll need water bottles, mineral oil, food coloring and water. Divide the students into pairs and assign one of each pair to be the writer and the other to be the illustrator. Fill the water bottles about one-fourth full with mineral oil. Add three drops of food coloring to the oil in each bottle, fill them with water, cap them and give them to the students. Explain that looking carefully at the oil and water in the bottles and describing it as a drawing is the first step. Ask them to draw a picture to record their observations. Ask them how they think the oil and water will mix and predict what will happen. Explain that this hypothesis and prediction is the question they will answer with this experiment. Have them spin the bottles slowly, then quickly, and then shake them. Explain that this is the experiment step that will show them what happens when trying to mix oil and water. Have them draw a picture showing the bottles after they shook them. Explain that they are drawing a conclusion about the mixing of oil and water. Ask them if their prediction turned out to be true. Have them perform the experiment again and see if the same thing happens. Explain that performing an experiment once is not enough to verify a conclusion.
Ice Turns into Water
This experiment teaches students how heat melts ice. You’ll need plastic cups, ice cubes, a windowsill or other warm place and a timer. Distribute a cup with an ice cube to each student. Have them draw a picture and write a quick description of the ice cube. Explain that they must carefully observe the condition of the ice cube before and after the experiment. Ask them what they think will happen to the ice cube if it is left in the sun or left in a cooler location. Have them record their hypothesis and prediction about what will happen. Set half of the cups on the windowsill to be warmed by the sun and half of the cups on your desk or another cool location. Set the timer for 15 minutes and instruct them to check their cups and record their observations each time the timer rings. After about 30 minutes, ask them draw a picture and write a description of their ice cube. Explain that they are drawing conclusions about ice cubes and how the warmer place made the cubes melt faster. In the next class have them repeat the experiment. You might want to switch windowsill and desk groups.
Ramp it Up
This experiment shows how fast different sized balls roll down a ramp. You’ll need a stopwatch, a board, a few books and ball. For variety, try a ping-pong ball, a tennis ball and a soccer ball. Clear a space for your ramp, stack the books and place one end of the board on the books. Ask the students to look very carefully at the set up and the balls, and record their observations. Ask them to come up with a question about how the different sizes of the balls will affect their travel time down the ramp. Have them record this hypothesis and predict how the balls will differ. Set a ball at the top of the ramp and let it go. Explain that you are about to start the experiment step. Time each ball’s travel to the bottom with the stopwatch or by having the students count, “one Mississippi, two Mississippi,” etc. Have them record the travel time for each ball and discuss how the sizes and weights of the balls affected their travel time. Replicate the experiment.
This experiment shows how distance affects our ability to see objects. You’ll need masking tape and magnifying glasses. Set up viewing stations with an object and a magnifying glass on each one. Mark distances of 1, 5, and 10 feet with masking tape. Label them “near,” “middle” and “far.” With the students standing at the 10-foot spot, ask them to describe what they can see. Have them record what they can see and ask them to predict what they will see at other distances. Have them draw what they can see at each distance and with the magnifying glass. Have them record and discuss how the distances affected their ability to see.
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