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Name:_________________________________________ Hr:_____

Unit 1: Scientific Method and Measurement Homework Packet

Part 1: The Scientific Method Applied

In 1928, Sir Alexander Fleming was studying Staphylococcus bacteria growing in culture

dishes. He noticed a mold called Penicillium also growing in some of the dishes. A clear area existed

around the mold. All the bacteria that had grown in this clear area had died. In the culture dishes

without the mold, no clear areas were present.

Fleming hypothesized that the mold must be producing a chemical that killed the bacteria. He decided to

isolate this substance and test it to see if it would kill bacteria. Fleming transferred the mold to a nutrient broth

solution. This solution contained all the materials the mold needed to grow and reproduce. He allowed the mold to

grow. Then he removed the mold from the nutrient broth. Fleming added the nutrient broth in which the mold had

grown to a culture of the bacteria. He observed that the bacteria died. Fleming then added nutrient broth that had not

had mold growing in it to another dish of bacteria. The bacteria in this dish did not die. Fleming concluded that the

mold produced a bacteria-killing substance. He called the substance that killed the bacteria penicillin.

1. Identify the problem Fleming wanted to solve. 2. What was Fleming’s hypothesis? 3. How did Fleming test his hypothesis? 4. What was the independent variable in Fleming’s experiment? Dependent variable? 5. What was used as the control group? ETSCIENTIFIC MET HODWHAT IS SCIENCE 1 6. What data did Fleming obtain? (Hint: what new information did Fleming find in his experiments?)

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7. What was his conclusion? 8. Did his data support his hypothesis? (Hint: did his experiment prove or not prove his hypothesis?) Explain 9. What was discovered as a result of Fleming’s experiment? 10. What is a theory? 11. How do hypotheses, observations, and conclusions relate to theories?

Part 2: Scientific Method with the Simpson’s

Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in

this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks.

Identify the:

1. Control Group ________________________________

2. Independent Variable _______________________________

3. Dependent Variable ________________________________

4. What should Smithers' conclusion be?

5. How could this experiment be improved?

Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this this out by spraying half of the shower with coconut juice. He sprays

the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower.

6. What was the initial observation?

Identify the: 7. Control Group ________________________________

8. Independent Variable _______________________________

9. Dependent Variable ________________________________

10. What should Homer's conclusion be?

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Part 3: SpongeBob’s Scientific Method

1) Marshmallow Muscles

Larry was told that a certain muscle cream was the newest best thing on the market and claims to double a person’s muscle power when used as part of a muscle-building workout. Interested in this product, he buys the special muscle cream and recruits Patrick and Sponge Bob to help him with an experiment. Larry develops a special marshmallow weight-lifting program for Patrick and Sponge Bob. He meets with them once every day for a period of 2 weeks and keeps track of their results. Before each session Patrick’s arms and back are lathered in the muscle cream, while Sponge Bob’s arms and back are lathered with the regular lotion.

a. Which person is in the control group?

b. What is the independent variable?

c. What is the dependent variable?

d. What should Larry’s conclusion be?

2) Microwave Miracle Patrick believes that fish that eat food exposed to microwaves will become smarter and would be able to swim through a maze faster. He decides to perform an experiment by placing fish food in a microwave for 20 seconds. He has the fish swim through a maze and records the time it takes for each one to make it to the end. He feeds the special food to 10 fish and gives regular food to 10 others. After 1 week, he has the fish swim through the maze again and records the times for each. a. What was Patrick’s hypothesis? b. Which fish are in the control group? c. What is the independent variable? d. What is the dependent variable? e. Look at the results in the charts. What should

Patrick’s conclusion be? 3) Super Bubbles Patrick and Sponge Bob love to blow bubbles! Patrick found some Super Bubble Soap at Sail-Mart. The ads claim that Super Bubble Soap will produce bubbles that are twice as big as bubbles made with regular bubble soap. Patrick and Sponge Bob made up two samples of bubble solution. One sample was made with 5 oz. of Super Bubble Soap and 5 oz. of water, while the other was made with the same amount of water and 5 oz. of regular bubble soap. Patrick and Sponge Bob used their favorite bubble wands to blow 10 different bubbles and did their best to measure the diameter of each one. The results are shown in the chart.

TIME PATRICK SPONGE BOB

INITIAL AMOUNT 18 5

AFTER ONE WEEK 24 9

AFTER TWO WEEKS 33 17

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a. What did the Super Bubble ads claim?

b. What is the independent variable?

c. What is the dependent variable? d. Look at the results in the chart.

o Calculate the average diameter for each bubble solution.

Super Bubble = ______ cm Regular Soap = ________ cm

o Based on the results, what should their conclusion be? e. Based on experiment setup, do you think the results are reliable? Why or why not?

Part 4: Largest/Smallest Metric Measurements

Directions: Circle the greatest metric measurement in each problem.

1) 500 cm 5000 mm 4 m

2) 0.2 L 240 mL 50 cL

3) 3000 mg 250 cg 3 kg

4) 4 L 5000 mL 23,000 cL

5) 17 m 17,040,000 cm 17,400,005 mm

6) 2000 cg 25,300 mg 2.5 kg

7) 3400 cg 4.5 kg 7,000,843 mg

8) 23 L 4.3 kL 6,000,320 mL

Directions: Circle the smallest metric measurement in each problem.

1) 500 cm 5000 mm 4 m

2) 0.2 L 240 mL 50 cL

3) 3000 mg 250 cg 3 kg

4) 4 L 5000 mL 23,000 cL

5) 17 m 17,040,000 cm 17,400,005 mm

6) 2000 cg 25,300 mg 2.5 kg

7) 3400 cg 4.5 kg 7,000,843 mg

8) 23 L 4.3 kL 6,000,320 mL

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Part 5: Metric Mania

Try these conversions, using the line/ladder/step method. If you have a problem with these STOP HERE! Please come see me to review before moving on. 1) 1000 mg = _______ g 2) 1 L = _______ mL 3) 160 cm = _______ mm 4) 14 km = _______ m 5) 109 g = _______ kg 4) 250 mL = _______ kL Conversion Challenge Write the correct abbreviation for each metric unit. 1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____

2) Meter _____ 5) Millimeter _____ 8) Centimeter _____

3) Gram _____ 6) Liter _____ 9) Milligram _____

Try these conversions, using the line/ladder/step method. 1) 2000 mg = __________ g 6) 5 L = __________ mL 11) 16 cm = __________ mm 2) 104 km = __________ m 7) 198 g = __________ kg 12) 2500 m = __________ km 3) 480 cm = ________ m 8) 75 mL = _________ L 13) 65 g = _________ mg 4) 5.6 kg = ________ g 9) 50 cm = ________ m 14) 6.3 cm = ________ mm 5) 8 mm = ________ cm 10) 5.6 m = ________ cm 15) 120 mg = ________ g Compare using <, >, or = 16) 63 cm______ 6 m 17) 5 g _______508 mg 18) 1,500 mL______ 1.5 L 19) 536 cm________ 53.6 dm 20) 43 mg _______ 5 g 21) 3.6 m _______ 36 cm

Part 6: Lab Safety Questions (Answer while watching safety video.)

Handling Chemicals Safely 1. When you read the label on a chemical container, what are the three most important pieces of information? 2. How many times should you read this information before you open the container? 3. Is it important to be exact when preparing a chemical reaction? EXPLAIN. 4. What should you do with leftover chemicals after an experiment? What should you do with the products of an

experiment?

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5. How can you draw small volumes of liquids into a pipette safely? 6. Why is it important to read the instructions all the way through before beginning an experiment? 7. When you need to carry chemicals from one place to another in the lab, what size container is the safest to use? 8. If you spill a liquid chemical, what should you do? 9. Should you add acid to water, or water to acid? Bunsen Burner and Glassware Safety 1. Before hooking a Bunsen burner to the gas line, what should you look for? 2. How quickly should you turn on the gas? 3. When you use a striker, where should you stand? 4. If your flame sputters or goes out, what should you do? 5. If you smell gas in the room, what should you do? 6. Is it safe to heat a sealed container? EXPLAIN. 7. Is it safe to work near heated objects?

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8. Is it safe to use glassware that has cracks or stars? EXPLAIN. 9. How can you safely carry a heated object? 10. Is it safe to heat flammable chemicals (e.g., gasoline) with a Bunsen burner? Thermometer Safety 1. Thermometers contain either alcohol or mercury to indicate temperature. Which substance (mercury or alcohol)

creates toxic vapors when exposed to air? 2. If you break a mercury thermometer, what is the safe way to clean it up? 3. Before choosing a thermometer for a specific job, what should you know? Dressing for Safety 1. What types of shoes are appropriate for the lab? 2. Describe the type of clothing you should wear on days when you will be working in the lab. 3. How should you protect your eyes from chemicals and glass shards? 4. Why is it important to remove rings, watches, and contact lenses before working in the lab? 5. How can you protect your hands when working with corrosive chemicals?

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Behavior in the Laboratory 1. Is the laboratory a safe place to eat, drink, or put on makeup? Why or why not? 2. What is the safe way to read a burette that is above your eye level? 3. Where should you keep your personal belongings that you bring to the lab? Emergency Equipment 1. Name the pieces of safety equipment in your laboratory. Do you know where they are and how to use them? 2. How do you extinguish a small fire in a container? What should you do if you have a larger

fire? 3. How do you put out a clothing fire?

Part 7: Dimensional Analysis

DIRECTIONS: Convert the following problems using dimensional analysis. You must show all work on a separate piece of paper to receive full credit. Staple your work to the back of this packet. Fill in your final answers in the blanks below.

1) 2 L =_____________mL 2) 20 mi = _____________km 3) 20 km = _____________mi 4) 500 in = _____________m 5) 500 m = ______________in 6) 0.5 g = _______________lbs 7) 0.5 lbs = ______________g

8) 50 yds = ______________m 9) 50 m = ______________yds 10) 16 g = ______________oz 11) 3.89 lbs = ______________g 12) 11.9 oz = _______________g 13) 2.3 lbs = ________________g 14) 23.8 lbs = _______________kg

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15) 0.050 lbs = ______________kg 16) 14 kg = _________________lbs 17) 135.4 g = ________________lbs 18) 14.2 oz = _________________lbs 19) 23.7 g = __________________oz 20) 4.3 lbs = __________________oz 21) 3.4 qts = ___________________L 22) 60 qts = ____________________L 23) 148 cm

3 = _________________mL

24) 14.3 L = ___________________qts 25) 9.4 ft = ____________________cm 26) 6.00 ft = ___________________cm

27) 11 in = ____________________cm 28) 1 in = _____________________m 29) 0.70 ft = ___________________m 30) 6.7 mi = ___________________km 31) 0.438 m = __________________in 32) 18.744 cm = _________________in 33) 5.67 m = ____________________ft 34) 2.80 cm = ___________________ft 35) 4.0 in = _____________________ft 36) 141 cm = ____________________ft 37) 13 km = _____________________mi 38) 2180 ft = _____________________mi

Part 8: Graphing Practice

Age of the tree in years

Average thickness of the annual rings in cm.

Forest A

Average thickness of the annual rings in cm.

Forest B

10 2.0 2.2

20 2.2 2.5

30 3.5 3.6

35 3.0 3.8

50 4.5 4.0

60 4.3 4.5

The thickness of the annual rings indicates what type of environmental situation was occurring at the time of its development. A thin ring usually indicates a rough period of development such as lack of water, forest fires, or a major insect infestation. On the other hand, a thick ring indicates just the opposite.

A. Make a line graph of the data.

B. What is the dependent variable? __________________________________________

C. What is the independent variable? ________________________________________

D. What was the average thickness of the annual rings of 40 year old trees in Forest A? Forest B?

Forest A :___________________________ Forest B :_____________________________________

E. Based on this data, what can you conclude about Forest A and Forest B?

_______________________________________________________________________________________

_______________________________________________________________________________________

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Title: _________________________________________________________________

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Part 9: Measurements (Use PRECISION for ALL MEASUREMENTS)

Part A Answer the following 3 questions for each graduated cylinder:

A) What is the size of the interval, in mL, between the finest marks? B) To what precision can you read the cylinder? (tenths, hundredths, whole number, etc) C) What is the volume of liquid in the cylinder? (All units are in mL)

1. 2. 3.

A)__________________ A)_________________ A)_________________

B) _________________ B)__________________ B)_________________

C) ________________ C) _________________ C)_________________

4. 5. 6.

A)__________________ A)_________________ A)_________________

B) _________________ B)__________________ B)_________________

C) ________________ C) _________________ C)_________________

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Part B

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Part C

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Part D