Transcript Matter
Matter Matter PA Standards 3.2.12.C: Inquiry and Design 3.4.10.A: Physical Science, Chemistry, and Physics 3.4.12.A: Physical Science, Chemistry, and Physics Apply the elements of scientific inquiry to solve multi-step problems. Explain concepts about the structure and properties of matter. Apply concepts about the structure and properties of matter. Objectives Distinguish between the physical and chemical properties of matter, and give examples of each. Perform calculations involving density. Explain how materials are suited for different uses based on their physical and chemical properties, and give examples. Question What are Chemical and Physical Properties of Water? Specific Heat Adhesion Straw Cohesion http://www.youtube.com/watch?v=1_OXM4mr_i0&feature=related Dropper and Penny Polarity Salt Plastic Distinguish between the physical and chemical properties of matter, and give examples of each. Physical Properties Physical properties - observe without changing the identity Chemical properties - substance combines with other elements or breaks apart to create new substance Melting/Boiling point the temperature and pressure at which a solid becomes a liquid/gas Three States of Water Examples Comparing Physical and Chemical Properties Characteristic properties help to identify and classify substances. • The table below compares some physical and chemical properties. Activity Complete the “Physical and Chemical Properties” Activity. Each person will have an example. Identify your example as a: Physical Property Chemical Property Physical Change Chemical Change Explain why your example is a physical/chemical property or change. After you have written your explanation, place your example next to the category it fits in. Perform calculations involving density. Demo Lab Finding Density Materials: Balance Small beaker Large beaker Golf Ball Graduated cylinder, 100 mL Salt Spoon Water Add water to a cup and add salt. Add salt until an egg floats. Determine the following: What is the density of the saltwater solution? (Density = mass / volume) What is the density of the golf ball? Compare your density measurements. What conclusions can you draw from this comparison? Physical Properties, Density the ratio of the mass of a substance to the volume of a substance Physical Properties, continued • The equation for density is D = m/V • • Density = mass/volume Units – grams per cubic centimeter (g/cm3) Activity Complete the Density Worksheet. Explain how materials are suited for different uses based on their physical and chemical properties, and give examples. Activity Read “Why It Matters: Aerogel” on page 53. http://www.youtube.com/watch?v=mAJWyRIDDVQ (19 minutes) http://www.youtube.com/watch?v=kHnen2nSmDY Writing Prompt: What are some physical properties of aerogel? NASA used aerogel to protect the Sojourner rover from the cold environment on Mars. What property makes aerogel useful for this purpose? How can aerogel improve energy efficiency in homes? Do the benefits justify the cost? Explain. Would you want aerogel as a part of your home? Why or why not? Physical Properties, continued Physical properties help determine uses. • Examples of useful physical properties include: • • • • • • low freezing point high boiling point water resistance flexibility electrical conductor heat conductor Chemical Properties Chemical properties describe how a substance reacts or how a substance changes into a new substance when in contact with other elements. Reactivity the ability of a substance to combine chemically with another substance Flammability the ability of a substance to react in the presence of oxygen and burn when exposed to a flame Reactivity Reactivity http://www.youtube.com/watch?v=oxhW7TtX IAM http://www.youtube.com/watch?v=l9z5mJ8NZk Thought Questions Identify the following as physical or chemical properties: Reacts with water Is red Is shiny and silvery Melts easily Boils at 100 degrees C Is nonflammable Has a low density Tarnishes in moist air Describe several uses for plastic, and explain why plastic is a good choice for these purposes. How could a product such as aerogel be used to increase efficiency in homes?