Lab Skills Review Run this PPT show to

Lab Skills Review Run this PPT show to help you review for your test.

1. The problem of an experiment is in the form of a ____. Question

2. A ______ is an educated guess to the problem of the experiment. Hypothesis

3. The ______ states whether your hypothesis is correct or incorrect. conclusion

4. What would make the results of an experiment carried out by a research team valid? The experiment was repeated and the same results were obtained each time.

5. The _______ group does not contain the independent variable. control

6. What is measured is known as the ______ variable. dependent

new idea that is tested in a scientific experiment is known as the ____. 7. A hypothesis

8. To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with a growth hormone. After 4 weeks of growth under ideal conditions, the plants were measured again. a. How would you set up the control group? There should be another group with 6 plants that DO NOT receive water.

8. To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with a growth hormone. After 4 weeks of growth under ideal conditions, the plants were measured again. b. Identify the independent and dependent variables. Independent: Growth hormone Dependent: Length of the seedling

8. To test the effect of hormones on plant growth, 6 potted plant seedlings of the same species were measured and then sprayed with a growth hormone. After 4 weeks of growth under ideal conditions, the plants were measured again. c. Give 2 factors that must be kept constant. The amount of water each plant receives. The temperature the plants were kept. The species of plant used. The amount of soil in each pot.

9. Identify the independent variable. 280 260 240 220 Water temperature 200 180 160 140 10. Identify the dependent variable. 120 100 80 60 40 20 Average water flea heart rate 5 35 10 15 20 25 30

11. State the relationship between the average water flea heart rate and water temperature. As water temperature increases, the average water flea heart rate increases (direct). 280 260 240 220 200 180 160 140 120 100 80 60 40 20 5 35 10 15 20 25 30

12. What is the average flea heart rate at 15ºC? 118 beats/min 13. What is the average flea heart rate at 30ºC? 240 beats/min 280 260 240 220 200 180 160 140 120 100 80 60 40 20 5 35 10 15 20 25 30

14. The results of one experiment carried out by a research team would be considered valid if a. the experiment had no control setup b. all the members of the research team came to the same conclusion c. the experiment had more than one variable d. the experiment was repeated and the same results were obtained each time

15. Why do scientists make graphs of data from experiments? a. to observe general trends and patterns in the data b. to make the observed data more accurate c. to prevent errors in measuring data d. to help change the original data tables

16. Which is the dependent variable in Amelia's experiment? a. the number of bean plants in each group b. the amount of water given daily to each plant c. the height of each bean plant d. the amount of fertilizer given to each group of bean plants

17. A new idea that is tested in a scientific experiment is known as a(an) a. theory b. hypothesis c. inference d. observation

18. Which statement about the use of independent variables in controlled experiments is correct? a. A different independent variable must be used each time an experiment is repeated. b. The independent variables must involve time. c. Only one independent variable is used for each experiment. d. The independent variables state the problem being tested.

19. An investigation is carried out to determine the effect of exercise on the rate at which a person can squeeze a clothespin. In this investigation, the independent variable is the a. control b. exercise c. rate of squeezing d. number of participants

20. An investigation is carried out to determine the effect of exercise on the rate at which a person can squeeze a clothespin. In this investigation, the dependent variable is the a. control b. exercise c. rate of squeezing d. number of participants

21. Why do scientists consider any hypothesis valuable? a. A hypothesis requires no further investigation. b. A hypothesis may lead to further investigation even if it is disproved by the experiment. c. A hypothesis requires no further investigation if it is proved by the experiment. d. A hypothesis can be used to explain a conclusion even if it is disproved by the experiment.

22. What is the definition of volume? The amount of space an object takes up. 23. What is the name of the instrument used to measure the volume of a liquid? Graduated cylinder

24. How is the volume of a liquid measured? Units? Use a graduated cylinder. m. L or L 25. How is the volume of a regular solid measured? Units? length x width x height cm 3

26. Calculate volume. Show all work! 2 cm 5 cm 3 cm V = l x w x h V = 3 x V = 30. 0 cm 3 2 x 5

27. Measure the volume of the liquid to the right. 67 m. L 28. the the Measure volume of liquid to left. 21 m. L

29. Measure the volume of the liquid to the right. 2 m. L 30. the the Measure volume of liquid to left. 49 m. L

31. What is the volume of this toy dinosaur? 0. 8 m. L (5. 6 m. L – 4. 8 m. L) 32. What is the name of this method? displacement

33. What is the definition of mass? The amount of matter in an object. 34. What is the name of the instrument used to measure mass? triple beam balance 35. What are the units used to measure mass? grams

36. Mass = 137. 4 gm

37. When using the Celsius scale: a. water freezes at 0°C b. water boils = 100°C c. human body temperature is 37°C

0 cm 1 2 3 4 38. What is the length of the object in millimeters? Centimeters? 8 mm 0. 8 cm

0 cm 1 2 3 4 39. What is the length of the object in centimeters? Millimeters? 2. 8 cm 28 mm

40. What is density? Mass per unit volume 41. How is the density of an object measured? Density = mass/volume

42. What is the density of one cup of water? 1 g/m. L 43. What is the density of half a cup of water? 1 g/m. L

44. What is the density of a 100 gram object with a volume of 20 milliliters? 5 g/ml 45. The object above was cut into three pieces. What is the density of one of those pieces? 5 g/ml

46. Explain why an object placed in a glass of water floats. The object has a density less than the density of water (1 g/ml).

47. Explain why an object placed in a glass of water sinks. The object has a density more than the density of water (1 g/ml).

48. Below is a list of the densities of different object. Will each one float or sink in water? a. 0. 38 g/cm 3 float b. 1. 7 g/cm 3 sink c. 1. 2 g/cm 3 sink d. 0. 99 g/cm 3 float e. 100 g/cm 3 sink

CONVERSIONS KILO (k) HECTO (h) DECA (da) METER (m) DECI (d) CENTI (c) MILLI (m)

49. Complete the following conversion: 21 hm = ____dm 00 0 = 21000 dm 21.

50. Complete the following conversion: 12 cm = ____m 12. = 0. 12 m

51. Complete the following conversion: 0. 45 m = ____ km 000 . 45 =. 00045 km