1. SCIENTIFIC METHOD REVIEW
Unit 1

2. 1ST STEP Ask a question or present a problem
Can’t experiment if you don’t have a problem.
What would be an example of a question or problem in science?

3. 2nd STEP Collect Information
Study, Research, Ask questions, Look at previous studies
Don’t want to do an experiment that has already been done.
Need information before you can decide how to experiment.

4. 3rd STEP So you know how to experiment and what to look for.
Form a hypothesis (an educated guess)
Why is it educated?
Why is it important to form an opinion about your problem?
So you know how to experiment and what to look for.
Can your hypothesis be wrong?

5. 4th STEP Test the hypothesis with an EXPERIMENT
Independent Variable: One thing you are testing/changing (graphed on the x-axis)
Dependent Variable: Measurable Outcome
(graphed on the y-axis)
Control: Has no independent Variable; used to compare to experiment
Constants: all other parts of your experiment that must remain the same in each setup.

6. 5th STEP Collect Data & Analyze Graph all the data
Hard to see patterns of numbers; graphs help
Study, Study, Study to see what your experiment showed

7. 6th STEP Draw a conclusion
Restate hypothesis and tell whether you have Proved or disproved your hypothesis
If you didn’t find an answer to your question, start with a new hypothesis or change your experiment.

8. Measurement & Problem Solving
Unit 1

9. Length The distance between two points Unit: meter, cm, mm, km
Tool: metric ruler or meter stick

10. Mass The amount of matter that makes up an object.
Unit: kilogram, gram, mg, cg
Tool: Triple beam balance
To use balance: Start with 100g bar, then the 10g bar, and finally the 1g bar. Make sure lines match up

11. Volume (liquid) The amount of space an object takes up
Unit: liter, mL, kL
Tool: Graduated cylinder
Meniscus is the bottom of the curve; make sure you get on eye level to take measurement

12. Volume (solids) Unit: Cubic centimeter (cm3)
Tool: ruler (length x width x height)
If it is an irregular shape, drop in graduated cylinder and see how much the water is displaced
1 mL = 1cm3

13. DENSITY Density - the amount of mass in a given volume of an object.
density = mass divided by volume
basic unit is g/mL for liquids or the g/cm3 for solid
determines if something sinks or floats
density of water is 1 g/mL anything higher will sink and lower will float.

14. Accuracy & Precision
Used to discuss the uncertainties of measured values.
Precision-a measure of how closely individual measurements agree with one another.
Accuracy-refers to how closely individual measurements agree with the correct or “true” value.
Example: Measurements in the science lab

15. Scientific Notation
To show how very large or very small numbers can be expressed using the power of 10
Move decimal point behind the first whole number
If move to the left, exponent will be positive; if move to the right, exponent will be negative

16. 93,000,000 becomes
9.3 x 107
becomes
7.897 x 10-6
Examples: Open your books
Page 116 example 5.2

17. Significant Figures
The numbers recorded in a measurement (all the certain numbers plus the first uncertain number)
Rules for counting significant figures:
Nonzero integers always count
Zeros: leading zeros never count; captive zeros always count; trailing zeros only if the number is written with a decimal point
Exact numbers: numbers not obtained using measuring devices but by counting – these have no limit

18. Practice Problems 0.0108g 0.0050060 5.030 x 103 110 riders 3 5 4
Unlimited
Page 126 self check

19. Rules for using Significant Figures
For multiplication & division: the number of S.F. in the answer is the same as the smallest number of S.F. in the problem.
a x 1.4 =  6.4
For addition & subtraction: the smallest number of decimal places in the problem will be used in the answer.
a =  31.1

20. Practice Problems 5.19 + 1.3 + 0.7833 1445-8.79 2.6 x 4.22
0.072/4.36
1 place past decimal
No places past decimal 2
Practice probs 129 self check

21. Metric prefixes kilo (k) = 1000 hecto = 100 deca = 10
root word (meter, gram, liter)
deci = 0.1 or (1/10)
centi (c)= 0.01 or (1/100)
milli (m)= or (1/1000)
micro()= or (1/1,000,000)
 move decimal 
0.005 km = 5 m = 500 cm = 5000 mm These values are all equivalent.
Example:
5km = _________ m; __________ cm
23cm = _______m; __________km

22. Conversion factors
METRIC-TO-METRIC: (*) can be substituted for meter, gram, or liter
1 k* = ____ *
1 h* = ____ *
1 Dk* = _____ *
1 * = _____ d*
1 * = _____ c*
1 * = _____ m*
1000
100 10 10
100
1000

23. Conversion Factors ENGLISH TO METRIC
 1 inch (in) = 2.54 cm
1m = 1.09 yards (yd)
1 km = 0.62 miles (mi) 
1 kg = 2.2 pounds (lbs)
1 L = 1.06 quarts (qts)
1 Newton (N) = 0.22 lbs

24. Dimensional Analysis
The use of conversion factors to change from one unit to another.
Write down what you know.
Draw chart
Fill in with conversion factors
Multiply across top
Divide across the bottom