In order for students to understand natural occurrences in their world, they must first understand the concept of matter. Matter in this context is defined as material substance that has mass and occupies space. (Trumbauer, 2007) In this portion of the unit, children will need to understand that matter can be present in our world in different states, matter is not created or destroyed, and that matter in different states behaves differently. (Abruscato, 2001)
Solids, liquids, and gasses of the same type of matter have the same molecules. What defines matter as solid, liquid or gas is the behavior of those molecules. Molecules in solid matter have a pattern that gives the solid a definite shape. This shape will not be changed unless acted upon by an external force. (Trumbauer, 2007) If you set a piece of paper on a table, alone it will not change shape; however, the piece of paper will change shape if a child tears or crumples it. The molecules in a solid are tightly packed and there are only slight vibrations rather than fluid movement. This is what causes a solid to hold its shape. (Abruscato, 2001)
The shape of a liquid is easily changed and takes the shape of the container that holds it. In addition, all liquids can be poured. (Trumbauer, 2007) Children can see this example in their own lunches. If a child has a carton of milk, the milk takes the shape of the carton. If the milk is poured from a carton to a glass it changes shape to fit the glass. When the glass gets knocked over on the table, it will continue to expand and flatten until the surface tension causes it to stop spreading. In a liquid, molecules have more room to expand and flow within the confines of the liquid. The molecules are touching but move faster and more freely than in a solid, giving liquid it’s flowing and formable properties.
Most gasses are invisible but they classify as matter because they have mass and take up space. This is evident when you think about the example of a balloon filled with air, or helium. When the balloon is filled with air, the air makes it expand and takes up the space within the balloon as it does with the helium. The air in the balloon has the same mass as the air surrounding the balloon, but the helium balloon rises because it has less mass than the surrounding air. Gas molecules move much faster and more freely than those of solids or liquids because they are not touching one another.
To demonstrate this to children, one could put marbles into a small bowl. If you put only a little energy into gently shaking the bowl back and forth, the marbles will be touching in the bowl and only move slightly back and forth while retaining their position in the bowl. This resembles the motion of the molecules within a solid. If you put more energy into shifting the bowl back and forth the marbles will shift back and forth in the bowl but they will continue to touch like a liquid. If you were to violently shake the bowl using even more energy, the marbles would break free from one another and spill out all over the room like the molecules within a gas.
Inquiry based lessons will give students crucial experience with matter. These experiences will be fundamental in preparing students to discuss phenomena that occur in nature. The experiments will help the students understand that matter can be present in our world in different states, matter is not created or destroyed, (Abruscato, 2001) and that matter in different states behaves differently.
Scope and Sequence
Day 1- Inquiry lesson- What is matter? -- The students need experience with matter in their own environment.
Day 2- Sort and discuss- What are the states of matter? -- Children sort different examples of matter.
Day 3- Introduction to molecules- model using magnetic marbles (see example above)
Day 4- Read or show United Streaming video The Magic School Bus Meets Molly Cule (see Student Resource list)
Day 5- Investigatory lesson- How long does it take to pour? -- Children can explore and graph the viscosity of different liquids in order to develop a concrete understanding that liquids can be poured (this lesson is described in detail in the lesson plan titled: How long Does it Take to Pour?).
Day 6- Investigatory lesson- Do gasses have weight and take up space? The teacher can tie a balloon full of helium to one end of a ruler and a balloon full of air to the other end of the ruler. Then the teacher can balance the ruler on his or her finger and let the children observe which balloon weighs more.