What would you do to find your lost dog?

Challenge: Find your lost chocolate chip cookie Problem: Can you observe and record some physical descriptions of your cookie and then later identify it from a pile of other cookies? Safety: Do not open the sealed bag and do not eat the cookie!

Success! Did you find your cookie? How did you do it? What characteristics did you use to help you identify your cookie?

Is it important to have good descriptions?

Identifying Matter by its Physical and Chemical Properties

Reviewing MATTER Mass – the amount of matter in something Matter: anything that has mass and volume Mass – the amount of matter in something Volume – the amount of space something occupies 7

Matter can be classified Element- substance with only one type of atom Compound- substance with two or more elements chemically bonded together. Natural-made by nature Synthetic-Man-made

What is a property? Property: a characteristic of a substance that can be observed You can describe or identify matter using its properties Properties of matter can be physical or chemical. 9

Physical and Chemical Properties can be used to identify matter Gold or fool’s gold? Diamond or quartz? Oak or Maple? Metamorphic or Igneous? Zinc or Aluminum?

Physical Property - A property that can be observed and measured without changing the material’s composition. 11

Physical Properties Mass - amount of matter in an object (grams). Weight – amount of gravitational force acting on an object. (N or lbs)

3. Volume - A measurement of the amount of space a substance occupies 3. Volume - A measurement of the amount of space a substance occupies. (mL or cm3) 4. Length - distance between two points (cm)

5. Color

6. Odor

7. Luster Luster – how the light is reflected (Shiny, glassy, dull, etc.)

Brittle materials are not malleable 8. Malleability Malleability- how easily it can be flattened into a sheet Brittle materials are not malleable

9. Ductility Ductility- ability to be pulled into a wire

10. Conductivity Conductivity- ability to transfer or conduct electricity.

11. Hardness (as measured on a Mohs scale)

12. Melting/Freezing/Boiling points Temperature at which the particles change phase

13. Density Amount of matter in a certain volume of material. (g/mL or g/cm3) Unknown metals can be identified by their densities.

14. State of Matter Solid, liquid, or gas phase - based on the arrangement and speed of the particles of matter.

You try it: Describe some physical properties of… A cookie A dog A diamond Water

Summary Physical properties can be used to identify matter. Physical properties can be observed and described without changing the material. http://study.com/academy/lesson/physical-property-of-matter-definition-examples-quiz.html

Physical Properties Lab Objectives: Can you use the physical property of density to correctly identify the material used to make each cube?

Conclusions How did you find the density? How do physical properties help us identify matter? Were there any problems with the measurements? Sinking objects have what type of density compared to water? 4 brass 1 acrylic 3 pvc 2 Al

Chemical Properties Matter can be described and identified by its physical properties (how it looks) and its chemical properties (how it reacts chemically).

Chemical Properties Chemical property: a property that can only be observed by changing the composition (chemical formula) of the material. How does it react with other materials? 31

Chemical property examples 1. Flammability- Will it burn?

2. Oxidation Oxidation- does it react with oxygen, usually forming rust.

Stainless steel (top) has a special coating on the metal that prevents oxidation. Regular steel (bottom) will oxidize more easily.

3. Reactivity How does it react with other chemicals? Example: do baking soda and baking powder have the same chemical reactivity when mixed with vinegar?

Summary Chemical properties can be used to identify matter To observe the chemical properties of matter, you must experiment with it - see how it reacts with other materials, then describe how it changed. (Did it burn, did it rust, did it react, etc.) https://www.youtube.com/watch?v=uJOGy0dgmUU

Properties of Matter - so what? Why do I care? Understanding the different properties of matter will help you to better classify and describe the world around you.