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Investigation and Experimentation. The Scientific Method, Lab Equipment, Measuring, and Lab Safety. Standards. - PowerPoint PPT Presentation
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Investigation and ExperimentationThe Scientific Method,
Lab Equipment, Measuring, and
Lab Safety
Standards• 1. Scientific progress is made by asking meaningful questions and conducting careful
investigations. As a basis for understanding this concept and addressing the content of the other four strands, students should develop their own questions and perform investigations. Students will:
• a. Select and use appropriate tools and technology (such as computer-linked probes, spreadsheets, and graphing calculators) to perform tests, collect data, analyze relationships, and display data.
• b. Identify and communicate sources of unavoidable experimental error.
• c. Identify possible reasons for inconsistent results, such as sources of error or uncontrolled conditions.
• d. Formulate explanations by using logic and evidence.
• e. Solve scientific problems by using quadratic equations and simple trigonometric, exponential, and logarithmic functions.
• f. Distinguish between hypothesis and theory as scientific terms.
• g. Recognize the usefulness and limitations of models and theories as scientific representations of reality.
Standards Cont.• h. Read and interpret topographic and geologic maps.
• i. Analyze the locations, sequences, or time intervals that are characteristic of natural phenomena (e.g., relative ages of rocks, locations of planets over time, and succession of species in an ecosystem).
• j. Recognize the issues of statistical variability and the need for controlled tests.
• k. Recognize the cumulative nature of scientific evidence.
• l. Analyze situations and solve problems that require combining and applying concepts from more than one area of science.
• m. Investigate a science-based societal issue by researching the literature, analyzing data, and communicating the findings. Examples of issues include irradiation of food, cloning of animals by somatic cell nuclear transfer, choice of energy sources, and land and water use decisions in California.
• n. Know that when an observation does not agree with an accepted scientific theory, the observation is sometimes mistaken or fraudulent (e.g., the Piltdown Man fossil or unidentified flying objects) and that the theory is sometimes wrong (e.g., the Ptolemaic model of the movement of the Sun, Moon, and planets).
The Scientific Method
Test the Hypothesis
Formulate a Hypothesis
Ask QuestionsMake
Observations
Design Experiment
Collect Data
Analyze the Data
Draw Your Conclusions
Measurements
Calculations, Graphs, Tables
Possible Explanations
Measure-ment
Units Units (abbrev.)
How we measure it
Length meters, centimeters, feet,
inches, miles
m, cm, km, ft, in,
mi
Ruler, measuring
tapeTime seconds, minutes,
hours, days, yearss, min,
hr, dy, yrClock,
stopwatchMass grams, kilograms,
pounds, ouncesg, kg, lb,
ozScale, triple
beam balance
Measure-ment
Units Units (abbrev.)
How we measure it
Volume milliliters, liters, cubic centimeters, cubic feet, gallons
mL, L, cm3, ft3,
gal
graduated cylinder
Temper-ature
degrees Celsius, degrees
Fahrenheit, Kelvin
°C, °F, K thermo-meter
Measuring Volume
Graduated Cylinders
Measure from the bottom of the meniscus (U-shape).
What is the volume of liquid in this graduated cylinder?
What is the volume of liquid in this graduated cylinder?
1 Notch below 800 mL, so…
about 790 mL
More Experiment Vocabulary
More Experiment Vocabulary
Converting Between Units(the Chemistry way)
• Even if you can do the conversion in your head or by only using a calculator, you need to practice following the steps.
• Eventually the problems in this Chemistry class will become too complicated to do without writing out the steps.
• You can still use a calculator, just save it for the last step.
• You will only get full credit for these questions by showing your work. You will get partial credit even if you got the wrong answer if you followed the steps.
Converting Between Units
? ft 10 in
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Step 1) Put what you are starting with over 1.
1
Converting Between Units
? ft 10 in
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Multiply it by the conversion factor as a fraction. Put the units that you are getting rid of on the bottom. Put the units you want on the top.
1 12 in1 ft×
Step 2)
Converting Between Units
? ft 10 in
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Cancel out the units that are on both the top and bottom.
1 12 in1 ft×
Step 3)
Converting Between Units
? ft 10 in
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Multiply everything on the top. Multiply everything on the bottom. Keep the units that have not been cancelled out.
1 12 in1 ft× 12
10= ft
Step 4)
Converting Between Units
? ft 10 in
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Divide the top by the bottom with a calculator to get a decimal.
1 12 in1 ft× = 0.83 ft12
10= ft
Step 5)
Converting Between Units
? L 2.5 gal
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Put what you are starting with over 1.
1
Step 1)
Converting Between Units
? L 2.5 gal
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Multiply it by the conversion factor as a fraction. Put the units that you are getting rid of on the bottom. Put the units you want on the top.
1 1 gal3.8 L×
Step 2)
Converting Between Units
? L 2.5 gal
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Cancel out the units that are on both the top and bottom.
1 1 gal3.8 L×
Step 3)
Converting Between Units
? L 2.5 gal
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Multiply everything on the top. Multiply everything on the bottom. Keep the units that have not been cancelled out.
1 1 gal3.8 L× = 9.5 L
Step 4)
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #1: Convert 78 centimeters to feet.
Put what you are starting with over 1.
1
Step 1)
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Multiply it by the 1st conversion factor as a fraction. Put the units that you are getting rid of on the bottom. Put the units you want on the top.
1 2.5 cm1 in×
Step 2)
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Cancel out the units that are on both the top and bottom.
1 2.5 cm1 in×
Step 3)
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Multiply it by the 2nd conversion factor as a fraction. Put the units that you are getting rid of on the bottom. Put the units you want on the top.
1 2.5 cm1 in×
Step 4)
12 in1 ft×
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Cancel out the units that are on both the top and bottom.
1 2.5 cm1 in×
Step 5)
12 in1 ft×
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Multiply everything on the top. Multiply everything on the bottom. Keep the units that have not been cancelled out.
1 2.5 cm1 in× 30
78= ft
Step 6)
12 in1 ft×
Converting Between Units
? ft 78 cm
1 ft = 12 in 1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Divide the top by the bottom with a calculator to get a decimal.
1 2.5 cm1 in× = 2.6 ft30
78= ft
Step 7)
12 in1 ft×