Study Guide: Measurement



Study Guide KEY: Measurement 2015

Part A: Measurements

1. Complete the table below. 1-5

|SI Base Units |

|Quantity |Definition |Base Unit |Device |

|Time |The interval between two |s |Clock, stopwatch |

| |occurrences | | |

|Mass |The amount of matter in a sample |kg |balance |

|Temperature |The average kinetic energy of the |K |thermometer |

| |particles | | |

|Length |The distance between two points |m |Meter stick, ruler |

|Amount of substance |Number of particles |mole |Periodic table |

6. The system of measurement used in science is the _International System_____________________ (SI).

7. The SI system of measurement consists of ___7_______ base units.

8. _Derived_____________ units result from the combination of two or more base units.

9. Give three examples of derived units. Volume, density, speed

10. The amount of space an object occupies is the _volume_______________. The device used to measure this value is the graduated cylinder, ruler_____________________.

Part B: Accuracy and Precision

1. The extent to which a measured value agrees with the accepted value is _accuracy_________________.

2. The extent to which a measured value agrees with others is __precision_________.

3. All measurements should contain _1_____ estimated digit.

4. Write the formula used when calculating % error.

Accepted – experimental x 100

accepted

5. The digits that are reported in an answer are called __significant digits__________.

6. Identify the number of significant digits in each of the following.

___3_____a. 105 000 cm _5____ b. 1.0040 mL ___4___ c. 0.007620 g

___5_____d. 320.00 mg __∞___ e. 20 books __ 3____ f. 4.20 x 104 km

7. Round 12.783456 to the requested number of significant figures.

a. 2 significant figures ______13________________ b. 5 significant figures ____12.783_____________

c. 6 significant figures ______12.7835________________ d. 7 significant figures ___12.78346______________

8. If the accepted value for the volume of a cube is 4.68 mL, determine the % error if a student concludes that the volume is 4.59 mL.

4.68 – 4.59 x 100 1.92 %

4.68

9. Record the measurements represented in the illustrations below:

[pic] [pic]

a. ____21.4 ml________________ b. _____2.32 cm_____________________________________

10. Three students made multiple massings of a copper cylinder, each using a different balance. The correct mass of the cylinder had been previously determined to be 47.32 g. Describe the accuracy and precision of each student’s measurements.

|Mass of Copper Cylinder (g) |

| |Lissa |Lamont |Leigh Anne |

|Measurement #1 |47.13 |47.37 |47.95 |

|Measurement #2 |47.94 |47.39 |47.91 |

|Measurement #3 |46.83 |47.35 |47.89 |

|Measurement #4 |47.47 |47.38 |47.93 |

Describe the Accuracy Describe the Precision

Lissa ____not accurate_________________ __not precise______________

Lamont____most accurate_____________ __most precise____________

Leigh Anne ___not accurate___________ __somewhat precise________

Part C: Graphing

1. The variable that is controlled by the experimenter is the __manipulated________ or _independent_________ variable. When graphing, this variable is placed on the __X____ axis.

2. The variable that changes as a result of the variable controlled by the experimenter is the _dependent________ or ___responding_____ variable. When graphing, this variable is placed on the ____Y________ axis.

3. The variables that are not changed during an experiment are called _control_____________ variables.

4. The __control___________ group is used as a standard of comparison with the experimental group.

5. The type of graph used to compare quantities is the __bar_________ graph.

6. The type of graph used when the data is in percentages is the __circle/pie_____________ graph.

7. The type of graph used to show changes or the relationship between two variables is the _line________ graph.

Use the following information for questions 8-10:

A student conducts an experiment to determine the effect of adding salt on the boiling temperature of water. The results are shown below.

|Sample |Amount of salt |Boiling Temperature |

|Sample 1 |0 g |100.0oC |

|Sample 2 |2 g |102.3oC |

|Sample 3 |5 g |104.8oC |

|Sample 4 |10 g |107.5oC |

8. What is the manipulated variable? __salt__ What is the responding variable? ___boiling temperature___________

9. What variables remained constant throughout the experiment? __amount of water, pots, stove setting_______

10. A. What conclusions can be drawn from the data? Increasing salt increases boiling temperature_________________

B. What is the predicted boiling temperature of the water when 7 g of salt are added?_106.2oC _________

C. If the boiling temperature of the water is 103.5oC, how much salt was added? ___3.5g___________

Part D: Scientific Method

1. A tentative explanation for observations that have been made is a __hypothesis_________________.

2. A set of controlled observations that tests a hypothesis is a(n) __experiment___________________.

3. At the end of an experiment, conclusions are based on the _results/data______________.

4. A tentative explanation that is supported by repeated experimental evidence is a _theory__________.

5. The two types of observations are __qualitative_______________ and ____quantitative__________. Which type involves a numerical measurement?___quantitative__________________________

6. Write the steps of the scientific method in order. _observation/question__________________, research________________________, ___hypothesis________________________, ____experiment_____________________, ____conclustion__________________________.

7. The number of variables that can be changed at a time in an experiment is ____one________.

PART E: LAB EQUIPMENT

Use the following terms to match with the pictures of lab equipment below:

[pic] [pic] [pic] [pic] [pic]

1-_Graduated

cylinder_______ 2- _Flask___ 3- _Beaker_____ 4- __Balance__________ 5- Test tubes and Rack__________

Identify 5 different incorrect lab safety practices in the picture below:

[pic]

Snake, Lindsey w/no goggles or gloves, food, inhaling toxic substances, scissors in socket, spill & broken glass, etc…

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