1. Units of Measurement Agenda  Review elements  Lab Reports Tuesday  Song  Notes on Units of Measurement & SN  Homework

2. F fluorine

3. O oxygen

4. selenium Se

5. N nitrogen

6. chlorine Cl

7. S sulfur

8. P phosphorus

9. Br bromine

10. strontium Sr

11. I Iodine

12. arsenic As

13. Ga gallium

14. aluminum Al

17. Percent error formula?

18. Units of Measurement Date:

19. Song

20. SI UNITS  International System of Units  Measurements used around the world so results are comparable.

21. Base Units  How would you define base units?  Basic unit of measurement

22. Length  Meter, m

23. Mass  Kilogram, kg

24. Amount of Substance  Mole, mol

25. Temperature  Kelvin, K  NO degree sign!  Absolute Temperature  no negative #  At absolute 0, all molecular motion stops  Celsius to Kelvin  o C + 273 = K  Celsius to Fahrenheit  o F = (9/5* o C) + 32

26. Derived Units  Define  A combination of base units

27. Volume m3m3m3m3  Length x width x height  Not very practical unit so we’ll use L  1 cm 3 = 1 mL  1000 L = 1 m 3

28. Density  Mass / volume  Kg/m 3  More practical g/mL

29. Pressure  Force / Area  mmHg, torr, kPa, atm

30. Reliability of Measurements  Accuracy: the closeness of a single measurement to its true value.  Hitting the bullseye.

31.  Precision: the closeness of a set of values to each other.

32. Measurement Exploration  Which measuring devices are more precise?

33. Basic Formula A * 10 exponent  A number between 1 and 10  If original number > than 1, exponent +  If original # < than 1, exponent -

34. Practice  3000  2653000  54600  130  0.000056  0.00456  0.07869  3.1415926

35. Homework