Physical Property • Any characteristic of a material that can be observed or measured without changing the composition of the substances in the material. • THINK/PAIR/SHARE: What are some words that you would use to describe the physical properties of matter? • Investigation: • Hold a sheet of newspaper horizontally. Now tear it in to strips. • Repeat, but this time hold the newspaper vertically. • Is there a difference in your ability to tear the newspaper? • Why? The molecules are chained together in a line. It is easier to separate the chains lengthwise than break the chains in half.
Chemical Property • Any ability a material has to produce change in the composition of matter. • THINK/PAIR/SHARE: What are some words that you would use to describe the chemical properties of matter? • Demonstrations:
Explaining Matter’s Properties • THINK/PAIR/SHARE: Why is matter so different? Why are there so many different kinds of matter? • The properties of matter are determined partially by how its particles are arranged. For example, the graphite in your pencil is made up of the same particles as a diamond, they are just arranged differently. • THINK/PAIR/SHARE: Can you use the properties of a known substance to help you identify an unknown substance? If so, then how would you do it? • Yes, of course you can use the properties of a known substance to identify and unknown substance! • The first step is to decide which properties to test. Then, carry out the tests on a sample of the unknown. Finally, compare the results with the data reported for known materials.
Explaining Matter’s Properties • Physical and chemical properties are used to … • identify a material • EXAMPLE: Water boils at 100oC at sea level • choose a material for a specific purpose • EXAMPLE: Copper is an excellent conductor of electricity and that’s why we use it for wiring. • to separate the substances in a mixture • EXAMPLE: You can pick all the Crunch Berries out of a cereal bowl because you like them the best! • Filtration is a process that separates materials based on the size of their particles. • EXAMPLE: Coffee or tea, Using a strainer • Distillation is a process that separates the substances in a solution based on their boiling points. • EXAMPLE: Converting saltwater to freshwater
Let’s Practice • Tools of the Physical Scientist – The Bunsen Burner Lab