1. Scientific Method and Units of Measure

2. Do Now
Write down the steps a scientist might use to solve a problem – this is called the scientific method.
Hint – there are 6 steps

3. Steps to the Scientific Method Organized Common Sense
Observing and stating the problem
Forming a hypothesis
Testing the hypothesis
Recording and analyzing the data
Forming a conclusion
Replicating the work

4. Scientific Method Video
YouTube - Chemistry Music Video 1: The Scientific Method
3 minutes

5. 1. Observing and stating the problem
Observation – leaves change color in autumn
Why????

6. 2. Forming a Hypothesis
Hypothesis – possible explanation, preliminary conclusion or even a guess about some event in nature
It gets cold and that causes the leaves to change color

7. 3. Testing the Hypothesis
Perform an experiment
- In July, take a small tree growing in a pot and place it in a growth chamber set to autumn temperature levels.
- If our hypothesis is right, the leaves should change color.
- If the leaves do change color, would we know if it was definitely due to the temperature?

8. 3. Testing the Hypothesis
Not really!!!
There are factors other than temperature that are different between our tree in the growth chamber and a tree growing outside.
Our tree is growing in a small pot.
Our light is not natural light.
Etcetera

9. Variable
A variable is the factor that is isolated and tested in an experiment.
In a good experiment, all factors other than the variable should be kept the same.
Our variable is the temperature in the growth chamber.

10. Types of Variables
Variables are things that may be expected to change during the course of the experiment.
The investigator deliberately changes the independent variable. (CAUSE)
He or she measures the dependent variable (EFFECT) to learn the effect of changing the independent variable.
To eliminate the effect of anything else that might influence the dependent variable, the investigator tries to keep standardized variables constant.  

11. Control
We need a control, which is the part of an experiment that does not contain the variable (temperature)
Grow a second tree in a pot an place it in a growth chamber also.
But, set the temperature in this chamber to normal summer temperatures.
Now, if the leaves change color we can be more sure it was due to the colder temperature.

12. 4. Recording and Analyzing Data
As you perform the experiment you must collect data by recording observations and information
In our experiment, we could count the number of leaves that changed color and the time it took for them to do so.
Then you must analyze the data by putting it in tables and graphs

13. Forming a conclusion Yahoo
Forming a conclusion Yahoo! Video Detail for Why do leaves change color in the fall?
Now we have to decide if our hypothesis is true.
We look at our data – does it support our hypothesis?
In our experiment, if only the leaves on the tree in the colder chamber change color, we may decide that we confirmed our hypothesis.
If the leaves of neither or the leaves of both trees change color, we may reject our hypothesis.

14. 6. Replicating the work
The original researcher must be able to reproduce the experimental results.
Other researchers should also be able to reproduce the experiment.

15. Hypothesis and theories
Theory – when a hypothesis is tested and confirmed often enough that it is unlikely to be disproved by future tests
Powerful time tested concept that makes useful and dependable predictions about the natural world

16. Activity – Identifying Variables
Read each scenario and figure out the
Independent variable
Dependent variable
Standardizing variables
Control Group
***Each student should hand in a completed copy of this work!

17. Graphing
A graph is a diagram representing a system of connections or interrelations among two or more things by a number of distinctive dots, lines, bars, etc
Graphs have an:
X axis (horizontal) – represents your independent variable
Y axis (vertical) – represents your dependent variable
It is a great way to present scientific data because it is easier for people to understand than a bunch of numbers

18. Graphing Activity
Complete the graphing activity “Scientific Method – Thumb Wrestling”
Measure and record your thumb length and circumference and your wrist circumference on your lab sheet and on the board
Pair off with a same sex student
Play 1 round of thumb wrestling
Winner moves on to play another winner, loser sits out
Play until there is only 1 female and one male winner left
Winners record data on board
Complete experimental data, analysis and conclusion and hand in.

19. Homework
Complete 2 review sheets
Study for test

20. A Universal Language – The Metric System
YouTube - Metric & Standard Measurement Systems

21. Metric System
Science works best when scientists read each other’s papers, check each other’s experiments, and argue about what results mean.
To do this they need a universal system of measurement to present their findings.
Scientists use the metric system of length, volume, mass, and temperature when describing experiments and data.

22. Metric System
Decimal system based on certain standards and scaled on multiples of 10:
Kilo – 1000
Basic Unit
Centi – 1/100
Milli – 1/1000
Micro – 1/1,000,000

23. Metric System Do you know the common metric units?? Length? Volume?
Mass?
Temperature?

24. Length Meter – basic unit of length in the metric system
Equivalent to 39.4 inches (a little longer than a yard)
Kilometer (1000 meters)
Meter
Centimeter (1/100 of a meter)
Millimeter (1/1000 of a meter)

25. Volume Volume - amount of space an object takes up
Cubic Meter – basic unit of volume for solids in the metric system
Liter – basic unit of volume for liquids in the metric system
Kiloliter (1000 liters)
Liter
Centiliter (1/100 of a liter)
Milliliter (1/1000 of a liter)

26. Mass and Weight Mass – measure of the amount of matter in an object
Weight – a measure of the pull of gravity on the mass
Weight can change – mass never changes (space)
Gram – basic unit of mass in the metric system
Kilogram (1000 grams)
Gram
Centigram (1/100 of a gram)
Milligram (1/1000 of a gram)

27. Temperature Celsius Scale – metric temperature scale
Water freezes at 0oC
Boils at 100oC
Each Celsius degree is 1/100 of the range between freezing and boiling
Normal Human Body Temperature is 37oC
Room Temperature is approximately 21oC

28. Metric System Activity
Get into your working groups
Complete the conversion worksheet
***Each student should place a completed copy of this work in their ISNB!

29. Metric Scale
Measurement Lab