1. UNITS OF MEASUREMENT SECTION 2-2

2. Objectives Distinguish between a quantity, a unit, and a measurement standard Name SI units for length, mass, time, volume, and density Distinguish between mass and weight Perform density calculations Transform a statement of equality to a conversion factor

4. mL g feet

5. Quantity has no meaning without the unit

7. length meter m

8. mass kilogram kg

9. time second s

10. temperature kelvin K

11. amount of substance mole mol

13. Liters L

14. V = L X W X H (cm3)

15. Graduated cylinder

16. Water displacement

17. Weight – measure of the gravitational pull on matter

19. Derived SI units Combination of SI base units Examples Area m2 L x W Volume m3 L x W x H Density Kg/m2 mass/volume Molar mass Kg/mol mass/mole

21. Density of Some Common SubstancesSubstanceDensity(g/cm3) Air 0.0013 Feathers 0.0025 Wood(Oak) 0.6 - 0.9 Ice 0.92 Water 1.00 Bricks 1.84 Aluminum 2.70 Steel 7.80 Silver 10.50 Gold 19.30

23. 1 dollar = 4 quarters

24. 1 kg = 1000 g

25. 1 Km = 0.6213 miles1 dollar4 quarters 4 quarter or 1 dollar

26. Making conversions How many miles are in 15 Km? Write given value: Choose conversion factor Multiply top and divide bottom 15 Km x 0.6213 miles = 9.3 miles 1 Km