2. Warm Up #1.1 1. The following data was collected. The volume of the gas is known to be 2.20 L. Use the words Precise and Accurate to describe the data. 2. How old are you in seconds?

3. Warm Up #1.1 Answer 1. Is precise but not accurate 2. Givens: xx years old Want: ? Seconds Need: 1 year = 365 days; 1 day = 24 hours; 1 hour = 60 minutes; 1 minute = 60seconds

4. Graphing Data Homework Worksheet

5. Variables Independent Variable: causes a change Dependent Variable: depends on independent Ex. Time is always independent… always changes Speed depends on the time  it’s dependent

6. X axis : Independent variable Y-axis: Dependent variable Slope: Rise/Run

7. Graph 1: Mass-Volume Slope: 2.70 g/cm 3 Independent: Volume Dependent: Mass Observations: its straight, one variable increases the other variable increases

8. Graph 2: Pressure- Volume Slope: varies Independent: Volume Dependent: Pressure Observations: opposite; one variable increases the other variable decreases

9. Conclusion: What are differences in graph 1 & 2 Graph 1: is a direct relationship Graph 2: is a opposite (inverse) relationship

10. Graph 1 is….. Directly Proportional

11. Graph 2 is …. Inversely Proportional

12. Practice: graph the data below Table 3: Cesium-137 Half- life Amount of sample (kg)Time (years) 1.0030.2 0.560.4 0.2590.6 0.125120.8 0.0625151

13. Graph 3: Cesium 137 Half Life Slope: varies Independent : Time Dependent : Amount

14. Units

15. Units of Measurement ALL measurements must include: # & unit

16. SI Units (International System of Units) Length= meter (m) Mass= kilogram (kg) Time= seconds (s) Temperature= Kelvin (K) *** K = C + 273 Pressure= pascal (Pa)

17. Prefixes PrefixSymbolValue Giga G 10 9 Great Mega M 10 6 Many Kilok 10 3 Kids Hecto H 10 2 Have Deka Da 10 1 Dropped Base Unit: g, L, m, s Over Deci d 10 -1 dead Centi c 10 -2 converting Milli m 10 -3 metrics Micro  10 -6 many Nanon 10 -9 nights

18. Significant Figures and Scientific Notation

19. Volume is?

20. Length is?

21. Uncertainty in Measurements When reading an instrument…  write all #s you see  + 1 more that you estimate

22. Rules for Significant Figures (sig figs) 1. Count all non-zero # s ex: a. 1234 = 4 sig figs b. 100 = 1 sig figs 2. Count zeros that are in b/w non-zero #s ex: a. 708 = 3 sig figs b. 1008 = 4 sig figs

23. 3. If # is less than one, count all # after the first non-zero # (do not count the zeros to the left of the first non-zero #) ex: 0.000987 = 3 sig figs 0.009870 = 4 sig figs

24. 4. If # is greater than zero & a decimal point is present, count all #s ex: a. 101.2 = 4 sig figs b. 1000.000 = 7 sig figs

25. Adding and Subtracting add or subtract the numbers keep all whole numbers round the decimal to the least number of decimal places

26. 5.00 cm - 4.352 cm 0.648 cm 0.65 cm

27. Multiplying and Dividing multiply or divide # s count the TOTAL number of sig figs in each Round to the least # of TOTAL sig figs

28. 6.7 cm x 1.1 cm 7.37 cm 2 7.4 cm 2 is the correct answer in sig figs

29. Practice 1. 708.0 – 89.49 = 618.51 = 2. 8.4 x 6.12345 = 51.43698 = 3. 6.8947 x 200 = 1378.94 = 4. 5.43 + 4.1 = 9.53 =

30. Scientific Notation In chemistry we often use very large or very small numbers. 54, 000 0.000008765 Mistakes are made with all these zeros so….. We use scientific notation.

31. Scientific Notation 1. Make the # <10 2. Count # of places decimal moves = exponent Ex: 54 000 = 5.4 x 10 4 3. If original # <1 the exponent is negative Ex: 0.000008765= 8.765 x 10 -6

32. Practice 1. 73,200 = 2. 23.21 = 3. 4, 713, 000, 000= 4. 0.00000000000043791=

33. Dimensional Analysis See Yellow Note Sheet

34. Dimensional Analysis 1. uses numbers in the form of fractions. 2. enables us to convert from one type of unit measurement to another.

35. Dimensional Analysis In order to convert from one quantity to another, we must use known quantities called Conversion Factors

36. Fractions = Conversion Factors Any number or any relationship can be made into a FRACTION, which is called a conversion factor in dimensional analysis. ex. 12 eggs in one dozen: 12 eggs = 1 dozen or 12 eggs or 1 dozen 1 dozen 12 eggs

37. Canceling Units If a unit appears in the numerator and the same unit appears in the denominator, it can be cancelled/ removed. Sometimes we need to invert to make this happen.

38. Set Up of Problems Must determine: 1. What is your GIVEN 2. What do you WANT 3. What do you NEED (conversions) (1)GIVEN (2)Conversion (3)what you WANT factor (s)

39. Prefixes PrefixSymbolValue Giga G 10 9 Great Mega M 10 6 Many Kilok 10 3 Kids Hecto H 10 2 Have Deka Da 10 1 Dropped Base Unit: g, L, m, s Over Deci d 10 -1 dead Centi c 10 -2 converting Milli m 10 -3 metrics Micro  10 -6 many Nanon 10 -9 nights

40. Warm Up 1.2- Warm Up 1.2- Round answer using sig fig rules 16.5 + 8 +4.37 = 28.87= 25.37 +6.850+15.07+ 8.056 = 55.346= 350.0 – 200 = 150= 0.58/ 2.1 = 0.2761904761904762= 6.54 x 0.37= 2.4198 = 0.0085 x 0.050 x 0.655= 0.655425=

41. Now you practice… 1. 0.56kg = ? mg 0.56 kg _______ g _______ mg = __________ mg kg g 2) 1.2ng = ? g 1.2 ng____ ____g = ___________ g ng

42. Now you practice… 1. 0.56kg = ? mg 0.56 kg _______ g _______ mg = __________ mg kg g 2) 1.2ng = ? g 1.2 ng____ ____g = ___________ g ng

43. 3) 2.0 in = ? mm (1in = 2.54 cm) 2.0 in _______cm ______ m ______ mm = ______ mm in cm m 4) 500ft = ? M 500 ft _______ in _________ cm _________ m = __________ m ft in cm

44. 5) 10μL = ? cc (1mL = 1cm 3 = 1 cc) 10μL _________L ________ mL _________ cc = _________ cc μL L mL 6) 3 wk = ? min 3 wk ___________ _____________________ = _______ min

45. 7) 50mL = ? cups (1L = 4.226cups) 50mL __________ _____________ = __________ cups 8) 5.33km = ? dm 5.33 km ____________ __________= ___________ dm

46. 9) 123.0 ng = ? Mg 123.0ng _____________ _____________ = ____________ Mg 10) 3yds = ? in (1 yd = 3ft) 3 yds ___________ _____________ = ______________ in