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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.
EXAMPLE PHYSICAL PROPERTIES Property Definition Color the wavelengths of light matter reflects Conductivity the ability to allow heat and electricity flow Density how tightly packed matter is in a certain amount of space Durability matter’s resistance to breakage Hardness the ability of materials to scratch one another Luster the ability of a metal to reflect light Malleability the ability of a solid to be hammered without breaking Mass the amount of matter an object contains Odor the way matter smells Solubility the ability to dissolve in water Temperature Changes (BP/MP) Texture as the temperature increases so does the speed of the particles. Particle speed determines if matter is a solid, liquid, or a gas. the way matter feels Transparency the property that enables light to be transmitted through matter a liquid’s resistance to flowing (usually decreases when temperature is increased) the amount of space occupied by an object Viscosity Volume
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: Property Definition Example Flammability the ability to burn in the presence of oxygen Oxygen Gas Reactivity the way one type of matter behaves when in comes in contact with another type of matter how readily a substance combines with other substances Potassium Iodide & Lead Nitrate Light Production the ability to create light Magnesium Gas Production the ability to create a gas Baking Soda & Vinegar Color Change the ability to cause a change in color Bloody Awesome Demo
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 100 o. C 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