Pure Substances and Mixtures Notes/Activities of Learning 1. Demo three states of matter in a closed system a. Ice cube floating in water in a jar with a lid b. Review prior knowledge Solid Liquid Gas Shape Keeps it Shape Takes the shape of Takes the shape of the container the container Volume Keeps its total Keeps its total Changes volume to volume volume fill its container 2. Write the words Pure Substance and Mixture in a Part/Whole chart on the board a. Have students write down a definition for each word and an example b. Share their definition with another group 3. Working Definition: a. A Pure Substance is made of one material Eg. sugar b. A Mixture is made of two or more materials Eg. Soil – a combination of different materials 4. Info Bit: Have students compare and observe similarities and differences between pennies before and after 1997. a. Before 1997 the penny was made of one material, copper b. After 1997 the penny was a combination of metals-­‐ a mixture. A mixture of metals is called an alloy. BRASS is an alloy. It is a mixture of zinc and copper. 5. Activity: Classifying Pure Substances and Mixtures a. Work with a partner to make a list of the 20 things you have used in the last two days (Include two solids, liquids and gases in your list) b. Classify your list into pure substances or mixtures add a third group if you are not sure. c. Continue the activity with samples of substances in clear containers in the classroom. Use the flowchart in your student notes to help you classify substances (see below). Student Notes What questions would you like answered to help you classify substances more accurately? Write your questions in your notes and on the board. Mixtures can be further classified into: Homogeneous Mixture is a mixture that looks the same (looks like one substance). Homo is a Greek word that means the same. Heterogeneous Mixture is a mixture that has clearly visible DIFFERENT parts. Hetero is a Greek word meaning different or unlike. Sometimes it is difficult to tell the difference between a pure substance and a solution without performing some scientific tests.