1. Ch 2 Matter and Energy

2. Convert 543 K into Celcius.

3. 269.85C

4. Calculate, then round (1.50 x 10 24 m)(4.611 x 10 5 m)= State the rule you used.

5. 6.9165000 x 10 29 m 2 = 6.92 x 10 29 m 2 least # of sig figs

6. Calculate, then round 9.78m + 112.0m= State the rule you used.

7. 121.78m= 121.8m Least # of decimal places

8. Convert 4.02 x 10 5 m to standard notation.

9. 402 000

10. Why do we need to round mathematic answers to specific values?

11. To reflect the least precise instrument in the measurements.

12. Evaporation H 2 O(l) → H 2 O(g) On which side should the energy appear in this physical reaction? Is this endothermic or exothermic?

13. Left Energy + H 2 O(l) → H 2 O(g) Endothermic

14. Convert -22°C to kelvin.

15. 251.15 K

16. Define specific heat capacity Then give it’s units.

17. the amount of energy needed to raise 1 gram of a substance 1 kelvin J/gK

18. The vibration of molecules of a solid is an example of ______

19. Chemical energy A type of kinetic energy

20. The energy given off when bonds form a new compound is an example of _______

21. Chemical Energy A type of potential energy turned into kinetic energy

22. A measurement that is very close to the true value is

23. Accurate

24. What do the significant figures in a measurement indicate?

25. The precision of the instrument

26. Explain the difference between a value with unlimited sig figs and a measurement.

27. A value with unlimited sig figs is an exact, counted value. It is not a measurement A measurement has an estimation as the final digit.

28. Give an example of a value with unlimited sig figs Give an example of a measurement

29. 1100 students at a school-exact 1100 seconds for a chemical reaction to occur- measurement

30. What’s the difference between making objective vs. subjective observations?

31. Objective-no bias (no opinion) Subjective- bias (opinion)

32. A student made a series of four measurements in the lab. Determine whether the measurements are accurate, precise, both, or neither. The actual value of the measurement is 200.0mL. 220.1mL, 220.3mL, 219.9mL, 220.2mL

33. Precise

34. What is the purpose of a control group in experimentation?

35. A control group provides a baseline for comparison.

36. True or False. When gasoline ignites, potential energy is converted to kinetic energy.

37. TRUE

38. Cell Transplant Falls Short A few diabetics have been able to give up their daily insulin shots after getting transplants of pancreas cells, according to the broadest study of this experimental treatment. But for most patients, the results fell short of the cure researchers have been seeking. Nearly half of the 36 patients who received the cell transplant achieved insulin independence by one year after the treatment. The benefits were mixed for the others, and about three-quarters of the whole group relapsed and needed insulin injections again.

39. What is the independent variable? What is the dependent variable? What other variables might affect the dependent variable? Could there be a control group? Explain.

40. IV: cell transplant DV: (not needing) insulin shots

41. Other variables? Genetics General health Diet Exercise

42. What is a double-blind experiment?

43. Neither the experimenter nor the subject knows if the subject is receiving a placebo

44. Read the graduated cylinder to the correct number of sig figs.

45. 32.6mL Don’t forget the unit!