Physical Science Learning Center Activities

Liquids

Two important concepts that children can learn relating to liquids are that (1) liquids have different properties that can be described and (2) liquids take the shape of the container they are in. To help children explore liquids, teachers might provide pictures or written task cards and materials so that children can do the following:

• Drop (dish soap, oil, honey, water, corn syrup, and vinegar) onto paper towels or coffee filters to examine the absorbency of different liquids.
• Drop a liquid onto different materials (cloth, newspaper, waxed paper, aluminum foil, construction paper) to see the absorbency of different surfaces.
• Look at the drops with a magnifying glass.
• Make the largest drop possible (children can use straws, basters, and eyedroppers).
• Make the smallest possible drop that can still be seen, using toothpicks.
• Add water to the different liquids to see what happens. Will the water mix with the other liquid?
• Drop color into the different kinds of liquids.
• Put water and oil in a bottle to examine density (vegetable oil floats because it is less dense than water; corn syrup sinks because it is more dense than water). Will the other liquids float or sink? What will happen if colored salt water is added to plain water?
• Classify several different kinds of liquids in jars by fluidity (i.e., how easy the substance flows).
• Discuss the characteristics of a liquid.
• Sort objects by whether they are a liquid or solid.

Bubbles

A bubble is a film of liquid surrounding a gas or air pocket. Two concepts that children can learn about bubbles are that (1) bubbles have air inside them and (2) air takes up space. Some bubble activities that children could complete in the science center to help them understand these concepts include the following:

• Divide objects into things that will make bubbles and things that will not make bubbles. Provide a variety of objects that might be used to make bubbles such as strawberry baskets, slotted spoons, sieves, funnels, wire bent into a closed circle, and wire bent into an open circle. Also provide laminated sorting sheets labeled with pictures and words for children to use in sorting the objects into those that will make bubbles and those that will not.
• Hold up the bubbles to the light to determine what colors can be seen.
• Make a pile of bubbles by using a straw to blow into the bubble mixture. Task cards might ask children to see what shapes are in the bubbles and to look at just one of the bubbles to see how many flat sides there are.
• Experiment to find out if different types of objects produce different shapes of bubbles (provide a variety of objects with holes in them such as sieves, square bubble blowers, tea strainers, funnels, and strawberry baskets).
• Create a bubble maker (provide wire, straws, string).
• Experiment with different bubble solutions (using different types of detergent, adding sugar to the bubble solution, adding glycerin to the bubble solution, adding white corn syrup to the bubble solution) to determine which makes the longest lasting bubble.

You will want to encourage children to record their experiments and write or draw what they did, dictate their findings to an adult, or share their finding at circle time.

Float and Sink

Floating and sinking combines the study of liquids with the study of solids. One of the “big ideas” for floating and sinking is that solids have properties. One of these is whether they sink or float in water. The teacher might introduce activities, or challenges, during group time or she might draw or write challenges on task cards for children to follow. These can be explored over a period of days or even weeks. Some activities for exploring this concept of sinking or floating include the following challenges:

• Divide the objects into those that will float and those that will sink. (Provide a variety of items, including items that are similar but different weights such as a ping-pong ball and a golf ball. Also, provide laminated sheets with pictures and words for sink and float that the children can use for their predictions.)
• Put the objects in the water to see if the predictions were correct.
• What are the similarities in the objects that sink? What are the similarities in the objects that float?
• Will a plastic film canister float? Does it float if you fill it with water? Does it float if you fill it with clay?
• Make a boat out of clay that will float. How many pennies can the boat hold?
• Make a boat out of tinfoil the same size as the clay boat. How many pennies can the boat hold?
• Redesign the boats so that they can hold more pennies.
• Can you make a straw sink?
• Predict which baby food lid will sink first (provide baby food lids with different sizes and patterns of holes).
• Design an object that will float for one minute and then sink.

Some common misconceptions that children have in regard to buoyancy is that objects float because they are lighter than water, they sink because they are heavier than water, wood floats and metal sinks, and all objects containing air float (Operation Physics, 1998). Buoyancy is determined by density, which is the mass divided by volume. If the item weighs more than the water it displaces, it will sink. As teachers, it is important that we understand these misconceptions, so that we can avoid reinforcing them when we work with children. We need to assess children’s understanding and scaffold their learning as needed. For example, we might want to include materials that help children to see that their misconceptions are not accurate (for example, a metal boat).

Movement

Some concepts that children learn about movement include “There are ways to make something move and to change the way that something is moving” (AAAS, 1993, p. 89). They are also learning that tools make work easier by altering the way the work is done. Children can learn about these concepts by moving water. Provide children with basters, eyedroppers, pumps, siphons, tubing, and funnels. Allow them to discover ways to move the water. In the beginning, it might be helpful to provide some examples to spark interest and provide some early success.

Children can explore many other movement activities to discover that “Things move in many different ways, such as straight, zigzag, round and round, back and forth, and fast and slow” (AAAS, 1993, p. 89). There are ways to make something move and to change the way that something is moving. “Things near the earth fall to the ground unless something holds them up” (AAAS, 1993, p. 94). Some of the materials you can add to the science center to help children explore the concept of movement include

• Marble rolls
• Lengths of rain gutters so that children can create ball rolls
• Pulleys, baskets, and ropes so that children can experiment with different ways of moving objects
• A pendulum
• Moving cars with an incline, placing different surface materials on the incline to experiment with the effects

Magnets

Two of the “big ideas” for magnets is that “magnets can be used to make things move without being touched” and that “forces can act at a distance with no perceivable substance in between” (AAAS, 1993, p. 94). Children can also learn specific information about magnets such as magnets attract some things and not others, magnets vary in strength, magnets can be a helpful tool. Below are some activities for exploring magnetism with preschool and early elementary age children.

• Explore a variety of items (screws, paper, buttons, aluminum foil, pennies, paper clips, rubber bands, scissors, eraser, dime, bottle cap) predicting and then testing theories about what is attracted to the magnet.
• Make a rule about the objects the magnet attracts.
• Determine which is the strongest part of a magnet by trying to pick up paper clips with different parts.
• Experiment with different magnets (bar, horseshoe, ring, rod) to see which is strongest. How many linked paper clips will each magnet pick up? Record results.
• Move metal shavings with a magnet. How far away can you be and still move the shavings?
• Will a magnet move a paper clip that is in water? Will it move a paper clip through a layer of cloth, through a piece of paper, or through a piece of wood? Complete a recording sheet. Circle the smiling face if yes, the magnet can move the paper clip, and a frowning face for no, the magnet cannot move the paper clip. Teachers can design the sheet by either drawing or taking a picture of someone conducting each experiment. For example, take a picture of a paper clip that is on top of a red piece of cloth with a magnet underneath. Place a smiling face and a frowning face beside each picture, so the child can circle the correct one.
• Find things in the classroom that are attracted to the magnet. Draw a picture of each thing you find.
• Experiment with toys that are magnetic (magnetic building blocks, magnetic sculpture, magnetic marbles, Magna Doodle toy). Teachers can also create their own toys with magnets. For example, attach a magnet to the bottom of a toy duck and place the duck in a shallow pan of water. The children can move the duck around in the water. Tie a magnet to a small tow truck and let the children tow the steel cars.

When choosing materials or activities to explore magnetism, it is important not to reinforce misconceptions. Common misconceptions that children have regarding magnets are that all metals are attracted to magnets, all silver colored items are attracted to magnets, all magnets are made of iron, and large magnets are stronger than small magnets (Operation Physics, 1998, p. 7). For example, Cora had placed magnets and a variety of materials in the science center. As she observed children using the center, she discovered that they had developed a hypothesis and, after testing their hypothesis, had concluded that shiny materials are attracted to the magnets. Cora then added some shiny objects to the center that were not attracted to magnets. This allowed children to reexamine their hypothesis. She also added a book that provided information about magnetism. Teachers can help children look up information when they have questions that they cannot answer. However, as this case illustrates, it is important that the teacher is knowledgeable enough about the topic to recognize children’s misunderstandings.