Question of the Day

1. Question of the Day Day 4 11-5 1. List and briefly define 3 “vocabulary” words from unit # 2 (this unit). 2. Why do we use scientific notation? 3. Solve: (3.0 * 103) ÷ (6 * 10-1)

2. TEST Day 4 11-5 FRIDAY 11-9!!!

3. POE Halloween

4. Question of the Day Day 5 11-6 1. List and briefly define 2 “vocabulary” words from unit # 2 (must be different than yesterday’s). 2. Solve: (3.0 * 103) + (6 * 102)

5. TEST Day 5 11-6 FRIDAY 11-9!!!

6. Accuracy vs. Precision Precision – repetition – if you do the same exp. or measurement over and over how close are the values. If something is precise it is repeatable

7. Accuracy vs. Precision Accuracy – accepted – measures how close your value is to the accepted or literature value

8. Accuracy vs. Precision You measure the density of 10 pennies and every time you get between 6.111 and 6.116 g/ml. You look up the density of a penny and find that it is 8.2 g/ml. What can you say about precision? Accuracy? What does this imply? Are you doing something wrong?

9. Accuracy vs. Precision Precision: An analysis = average deviation Accuracy: An analysis = percent error

10. Accuracy vs. Precision Precision: An analysis = average deviation DEVIATION X = MEAN X – X The absolute value of the difference between a measurement and the average (mean)

11. Accuracy vs. Precision If your average deviation is small relative to your measurements it indicates that your measurements were all close together or… Precise

12. Accuracy vs. Precision Calculating average deviation: Measurements: run # 1 – 7.51 cm run # 2 – 7.55 cm run # 3 – 7.49 cm run # 4 – 7.58 cm 1. Calculate average 7.53 cm 2. Calc. deviations for each run

13. Accuracy vs. Precision 2. Calc. deviations for each run X – X run # 1 → 0.02 cm run # 2 → 0.02 cm run # 3 → 0.04 cm run # 4 → 0.05 cm run # 1 → 7.51 cm – 7.53 cm = run # 2 → 7.55 cm – 7.53 cm = run # 3 → 7.49 cm – 7.53 cm = run # 4 → 7.58 cm – 7.53 cm = 3. Calc. average deviation

14. Accuracy vs. Precision 3. Calc. average deviation run # 1 → 0.02 cm run # 2 → 0.02 cm run # 3 → 0.04 cm run # 4 → 0.05 cm 0.03 cm = 3 * 10-2 cm

15. Accuracy vs. Precision Calculate the average deviation for the shoe sizes of the 4 people sitting closest to you in your notes (SHOW ALL WORK!). How could you have gotten a lower average deviation?

16. Accuracy vs. Precision Accuracy: An analysis = percent error Measured – accepted % error = X 100 accepted Period 7 left off Monday 11-5

17. Accuracy vs. Precision If your % error is small compared to your measurement that indicates that the measurement was close to the accepted value or… Accurate

18. Accuracy vs. Precision Calculating % error: Measurement: 7.51 cm Accepted value: 7.33 cm Measured – accepted % error = X 100 accepted

19. Accuracy vs. Precision Calculating % error: Measured – accepted % error = X 100 accepted 7.51 cm – 7.33 cm % error = X 100 7.33 cm 2.5%

20. Review Homeworks AND Notebooks

21. Question of the Day Day 5 10-4 • Joey measures the density of water in lab and calculates a 1% percent error. • What can you say about his accuracy? • What can you say about his precision?

22. Review Homework

23. Tic-Tac-Toe  Battle of the Sexes What is the density in g/ml if the mass is 0.0060 kg and the volume is 30 dL? How does the arrangement of particles determine density? If a measurement is accurate that means …? The branch of chemistry that seeks to identify unknowns = ? 8.71 + 7.1 Take out of sci. not.: 4.00 * 106 Explain why we use scientific notation. If a test tube contains a pink liquid over a green liquid over a yellow liquid, how do the densities of the liquids compare? FREE SPOT (4.0*104)*(5.0*10-1) Explain why we use sig. figs. Take out of sci. not.: 4.00 * 10-6 5.00 * 2.0 8.5 / 2.0 (4.00*104)-(3*102) You saw me drop ice in alcohol, put the following in order of INCREASING density: water, alcohol, ice cube The discipline that seeks to explore and explain = ? Absolute zero = _____ K _____ °C Convert: 5.50 mg = __ µg Is air matter? How do you know? A scientist studies the digestion of diabetics - what branch of chemistry? The branch of chemistry associated with laws, models, and equations ? The branch of chemistry associated with carbon = ? Define density without using the words mass or volume. (3.0*104) / (4*10-1)

24. Tic-Tac-Toe  Battle of the Sexes What is the density in g/ml if the mass is 0.0060 kg and the volume is 30 dL? How does the arrangement of particles determine density? If a measurement is accurate that means …? The branch of chemistry that seeks to identify unknowns = ? 8.71 + 7.1 Take out of sci. not.: 4.00 * 106 Explain why we use scientific notation. If a test tube contains a pink liquid over a green liquid over a yellow liquid, how do the densities of the liquids compare? FREE SPOT (4.0*104)*(5.0*10-1) Explain why we use sig. figs. Take out of sci. not.: 4.00 * 10-6 5.00 * 2.0 8.5 / 2.0 (4.00*104)-(3*102) You saw me drop ice in alcohol, put the following in order of INCREASING density: water, alcohol, ice cube The discipline that seeks to explore and explain = ? Absolute zero = _____ K _____ °C Convert: 5.50 mg = __ µg Is air matter? How do you know? A scientist studies the digestion of diabetics - what branch of chemistry? The branch of chemistry associated with laws, models, and equations ? The branch of chemistry associated with carbon = ? Define density without using the words mass or volume. (3.0*104) / (4*10-1)

25. Leave your notebook if you are...

26. Measured – accepted % error = X 100 accepted Measure me 1 2 3 4 5 6 7

27. Q of the Day Day 1 10-6 What test version did you take yesterday? Prelab

28. Q of the Day Day 6 10-5 Get out your review homework and clear your desk!

29. Homework ?s Unit # 1 Test is Wed. 10-5

30. Discussion Partner Review Unit # 1 Test is Wed. 10-5