Scientific Method, Metric Measurement, and Lab Safety

1. Scientific Method, Metric Measurement, and Lab Safety Review

2. Students plan to use thermometers to compare average monthly temperature in Madison Heights and Richmond. Which of these variables should be manipulated? Location of the thermometer Brand of the thermometer Size of the thermometer Type of the thermometer

3. ______ can be measured with a graduated cylinder in milliliters or liters. Density Volume Weight Mass

4. A student is trying to determine which temperature causes bread dough to rise the highest. He puts one ball of dough at 30°C and the other at 40°C. At the end of an hour, he measures the height of each ball of dough. Which of the following is the dependent variable? temperature Bread dough height mass of dough type of dough

5. You are heating a piece of glass and now want to pick it up. You should use a rag or paper towels. pick up the end that looks cooler. use tongs. pour cold water on it.

6. A scientist testing the effects of a chemical on corn production sprays a field with the chemical. A second field does not receive the chemical. The number of ears of corn harvested from each field is counted. Which of the following is the dependent (responding) variable in the experiment? the amount of chemical sprayed the first field the number of ears of corn the second orchard

7. In order for the corn field experiment to be valid scientifically, both fields must: receive the same amount of sunlight receive the same amount of water have the same species of corn all of these

8. An educated guess that has not been proven, but is based on knowledge is called what? an experiment a theory an observation a hypothesis

9. Which tool would you use to measure the mass of an object? meter stick graduated cylinder triple beam balance calculator

10. The scientific method is a process for experimentation that is used to explore observations and answer questions. What is the first step in completing the scientific method? conduct an experiment research identify problem form a hypothesis

11. Sunfish were studied to determine if the water temperature affected the reproduction of these fish. Which of these was the independent variable in this study? The water temperature The amount of nutrients in the water The length of time required for reproduction The number of fish produced by each parent

12. How many milligrams are in a gram? 10,000 1,000 100 10

13. As part of an experiment to measure decomposition rates of different materials, students put food scraps from the cafeteria in compost bin A and leaves and grass clippings in compost bin B for six weeks. Students in first period measured the temperature in bin A, and students in sixth period measured the temperature in bin B. What is the greatest error in the students’ experimental design? Temperature is the only dependent variable in the experiment. The materials chosen decompose too rapidly. There are too many uncontrolled variables in the experiment. The students put equal masses of materials in each bin. Diagram

14. When smelling a liquid inhale deeply. waft it toward you. use the fume hood. pour it on the table.

15. A student notices that the evening sky is usually red. He wants to find out why. Which of the following would be the next step? He starts to experiment to see how dust affects light rays.   Other scientists confirm his experiments. He thinks that dust in the sky makes the sky red. He publishes an article on sky conditions.

16. Long hair in the laboratory must be cut short. always neatly groomed. tied back or kept entirely out of the way with a hair band, hairpins, or other confining device. held away from the experiment with one hand.

17. A student hypothesizes that sunflowers will grow fastest when given fertilizer. To test this hypothesis, the student should design an experiment with which independent variable? Species of sunflower Rate of sunflower growth Amount of water given to each plant Whether fertilizer is used or not

18. The diagram shows a plant investigation. Which is the independent variable? Hours of light exposure Soil pH Plant species Soil volume

19. The data show the growth of two rose plants over several weeks using four different fertilizers. The experimental data would be more valid if which of the following variables was included in the experiment? A fifth fertilizer was tested. Only one plant was tested. A control without fertilizer was included for each plant. The plants were grown at variable temperatures. Table

20. Jan consistently read the volume of liquids as shown. How would this practice impact her work? • Her measurements would be too high. • Her measurements would be too low for less dense liquids. • Her measurements would lack precision. • Her measurements would be very accurate.

21. If you do not understand a direction or part of a lab procedure, you should figure it out as you do the lab. skip it and go on to the next part. try several methods until something works. ask the instructor before proceeding.

22. When using a test tube to heat substances, be sure that the open end points toward a classmate. your teacher. no other person. yourself.

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