1. Descriptive Properties of Matter

2. Include two types of Observations Qualitative Gives results in a description, nonumerical form Gives results in a description, nonumerical form Quantitative Give results in a definite form, usually numbers and units Give results in a definite form, usually numbers and units

3. Accuracy vs. Precision Accuracy - how close a measurement is to the accepted value Precision - how close a series of measurements are to each other ACCURATE = CORRECT PRECISE = CONSISTENT

4. Accuracy vs. Precision

5. Density Mass Volume Density = What are the units for each? g mL g/mL Types of Values Accepted Value – the ‘book’ value, what the value is supposed to be. Experimental Value – the value found in the lab.

6. Percent Error Indicates accuracy of a measurement your value accepted value A student determines the density of a substance to be 1.40 g/mL. Find the % error if the accepted value of the density is 1.36 g/mL. % error = 2.9 %

7. Physical Property - can be observed without changing the identity of the substance Extensive property – physical property that depends on the amount of the substance – Examples: mass, volume, length Intensive property – physical property that is not dependent of the amount of substance. – Examples: Density, color, melting point Chemical Property – often can not be observed without changing the identity of the substance; involves electrons at the atomic level

8. Classification of Matter Matter is anything that has a mass and volume. Mass is the amount of matter the object contains. Volume is the amount of space an object takes up. Examples of things that are not matter: – Light and energy Picture a Golf Ball and a Ping Pong Ball… Which has more mass? More volume?

9. Differences between Mass and Weight Mass Weight 1. Is always a constant at any place and time Depends on gravity at the place 2. Is measured in kilograms in SI unitIs measured in Newtons (not in kilograms as one might think) 3. Is measured using balanceIs measured using scales 4. Can never be zeroCan also be zero 5. Is an intrinsic property of a body and is independent of any external factor. Depends on 1. Mass of the object which is attracting it 2. Force with which it is being attracted (which in turn depends on the distance between the two)

10. States of Matter Solid – definite shape, definite volume; little movement of particles. Liquid – indefinite shape, definite volume; some movement of particles. Gas – indefinite shape, indefinite volume; lots of movement of particles.

11. Matter’s Changes and Properties Physical Property – can be observed without changing the identity of the substance color texture density viscosity change in state solubility malleability mass volume Chemical Property – describes the ability of a substance to undergo changes in identity – A new substance is produced reactivity toxicity pH conductivity tarnishing fermenting Oxidation flammability There are properties that are used to describe matter.

12. Density Problems 1.What is the volume of a tank that can hold 754 g of methanol whose density is 0.788 g/cm 3 ? 2.What is the density of a board whose dimensions are 5.54 cm x 10.6 cm X 19.9 cm and whose mass is 28.6 Kg? 3.The density of silver at 20ºC is 10.5 g/cm 3. What is the volume of a 68 g bar of silver?