1. CH 1: The Nature of Science
What is science?
AIM: What are the methods we as amateur scientists will use to conduct our studies and what measurements will we use to conduct these studies?
OBJECTIVES:
Identify steps scientists often use to solve problems.
Distinguish between dependent and independent variables.
Identify metric units for mass, length, time, temperature, and density. (ACOS 12)
Tell the students about the book website listed above. It has SF links, extra questions, etc.
Have the students complete the explore activity on page 5.
Have the students draw the table, fill it in, then answer the Observe question.
Discuss the importance of having standards of measurement.
Ask the students “What is science?” Write their answers on the board. See if the class can come up with a definition of science.

2. Section 1: The Methods of Science
Science is a method for studying the natural world.
Science is a process that uses observations and investigations to gain knowledge about events in nature.
Science has branched into the world of technology which is not what we normally think of as the natural world. So, in reality, science is the study of anything.

3. Major Categories of Science
life science
Study of living things
Earth science
Study of Earth and space
physical science
Study of matter and energy
Science covers many different topics that we will classify to three main categories, that very often overlap.
Pic 1—life (study the way the grass and tree grow and the effects of the environment on them)
Pic 2—earth (study the effects of pollution on earth, etc)
Pic 3—heat (study the structure of the materials through which heat travels, why heat travels through them, and what heat really is)
Pic 4—life and physical

4. Scientific explanations help us understand the world around us
Scientific explanations help us understand the world around us. Sometimes, these explanations must be changed. As we study more and more, and as new technology arises, our previous explanations might need updating or changed.
Ask students “How does heat act like a fluid?”
Read two paragraphs about Figure 2 on page 7.

5. What are investigations?
Scientists learn new information about the world through investigations.
What are investigations?
Scientists often follow a general pattern when conducting investigations.
What are investigations? (observations, modeling, experimentation)

6. Scientific Method
The scientific method is an organized set of investigation procedures.
A scientist can add new steps, repeat some steps several times, or skip a step completely when doing an
investigation.
Before 1st bullet: Ask students how they found their different classes on the first day of school. Explain that these methods are analogous to the way the scientific methods used by scientists.

7. Research and gather information.
State the problem.
Research and gather information.
Form a hypothesis.
hypothesis: possible explanation for a problem (a prediction) using your previous knowledge and observations
You must be able to test your hypothesis.
This is the Why? of the method. This is where we state the purpose for our investigation. Example: I want to hang a poster on the concrete wall. I don’t know what method would be best for hanging the poster that will help it stay the longest.
It is very useful to learn as much as possible about the background of a problem before beginning an experiment. Example: I would research different methods of hanging things on concrete and the advantages and disadvantages of each or problems that could be associated with each.
A hypothesis is an educated prediction using the research that you have completed and previous knowledge you have about the problem. Example: I hypothesis that concrete nails will hold the poster the longest.

8. Test the hypothesis. Make observations.
Build a model and relate it to real-life situations.
Perform an experiment (test the effects of one thing on another using controlled conditions).
After 1st click: This is the “meat” of the method. This can be done in several ways.
After 2nd click: This could be like watching birds and their mating rituals, observing ants in an ant farm, etc. What is the benefit of observations?
After 3rd click: This could be building 3-D models or computer models. What is the benefit of computer models?
After 4th click: This is the most active approach. Controlled conditions is the key. We will discuss this in detail later.

9. Analyze the data. Draw conclusions.
If your conclusion does not support your hypothesis, you need to reconsider your hypothesis and:
Revise the hypothesis or
Conduct your experiment differently.
5. Observations must be recorded (in your project notebook) and the test data organized into easy to read tables and graphs.
When you are making and recording observations, you should include all results, even unexpected ones. Many important discoveries have been made from unexpected outcomes.
The data is interpreted and analyzed.
Based on the analysis of your data, you decide whether or not your hypothesis is supported.
For a hypothesis to be considered valid and widely accepted, the experiment must result in the exact same data every time it is repeated.
Have the students work with a partner to design a mnemonic device to remember the six step scientific method.

10. Variables, Constants and Controls
variable—changeable factor in an experiment
dependent variable: variable that changes according to changes in other variables
independent variable: variable that is changed by the experimenter
constant—factor that does not change in an experiment
control—standard by which the tests can be compared
Before 1st bullet—An experiment usually contains at least two variables.
The dependent variable depends on an independent variable.
The independent variable affects the dependent variable.

11. You are going to plant some tomatoes this summer
You are going to plant some tomatoes this summer. You plan to set up an experiment to determine which of three fertilizers helps your plants to grow the biggest. You plant four tomato plants in four different pots. In the 1st pot, you use no fertilizer, 2nd you use fertilizer A, 3rd-fertilizer B and 4th-fertilizer C. You make sure that each plant receives the same amount of sunlight and water. After four weeks, the 3rd plant has grown the biggest.

12. What is the dependent variable? What is the independent variable?
What are the variables?
growth of plant, type of fertilizer
What is the dependent variable?
growth of plant
What is the independent variable?
type of fertilizer
What are constants in this experiment?
sunlight, water, tomatoes, soil
What is the control?
Pot 1

13. Scientific experiments must meet the following criteria to be truly valid:
must have data that are measurable
must be repeatable
Read the following:
Being Objective page 10
Visualizing with Models page 11
Limitations of Science page 12
Using Science-Technology page 13
An experiment’s results don’t mean much if another scientist can’t perform the same experiment and get the same results.
Have the students answer the Section 1 Assessment on page 13, questions 1-7.

14. Section 2: Standards of Measurement
standard—exact quantity that people agree to use for comparison
Most nations of the world use the metric system—a system of measurement based on multiples of 10.
SI—improved version of the metric system accepted everywhere and understood by scientists throughout the world
Ask the students: What did we learn from our explore activity at the beginning of this chapter? (that we need standards of measurement)
After 2nd bullet: The metric system was devised by a group of scientists in the late 1700s.
In 1960, an improved version of the metric system was introduced.
Each type of SI measurement has a base unit. Table 1 page 15 Know the 1st five.
All other SI units are derived from these.

15. SI prefixes are used with the names of the units to indicate what multiple of 10 should be used with the units.
1 kilogram  1000 grams
1 hectogram  100 grams
1 dekagram  10 grams
gram, meter, liter
10 decigrams  1 gram
100 centigrams  1 gram
1000 milligrams  1 gram

16. Example Problems
You have a length of rope that measures 3075 mm. How long is it in cm?
307.5 cm
Your pencil is 11 cm long. How long is it in millimeters?
110 mm
You have 55 mL of Pepsi. How many L do you have?
0.055 L

17. Mass—measure of the amount of matter in an object
Distance (length)
unit: meters
Measured with ruler or meterstick
Mass—measure of the amount of matter in an object
unit: kilograms
Measured with a balance
Time
unit: second
Measured with a stopwatch or clock

18. Volume volume—amount of space occupied by an object
Volume = length x width x height
Solid = cm x cm x cm = cm3
Liquid = mL or L (1 mL = 1 cm3)

19. Density Density = mass / volume
What is the density of a cube with a mass of 0.45 g and a volume of 0.15 cm3?
3 g/cm3
What is the density of an object having a mass of 10 g and a volume of 2 mL?
5 g/mL
Density is a derived unit b/c it is a combination of SI units.

20. Temperature Unit—Kelvin (K)
0 K is the coldest possible temperature—also known as absolute zero
0 K = oC
C  K C = K
C  F C x = F
F  C F – 32 / 1.8 = C