1. The World of Physical Science
Chapter 1
The World of Physical Science

2. What is Science?
Science is a process of gathering knowledge about the natural world.
What are some of the different types of sciences that a person can study?

3. Science
Life
Earth and Space
Physical
Biology
Astronomy
Physics
Chemistry
Anatomy
Meteorology

4. What is Physical Science?
Physical science is the study of matter and energy.
Matter is made up of atoms and has both a mass and volume.
Energy is the ability to do work.
The branches of physical science
Chemistry
Physics

5. Chemistry
Chemistry is the study of all forms of matter, including how matter interacts with other matter.
Chemistry looks at the structure and properties of matter.

6. Physics Physics looks at energy and how that energy affects matter.
Motion, force, gravity, electricity, light, and heat are parts of physics.

7. Many sciences use chemistry and physics (the physical sciences)
Meteorology – the study of weather uses physics to understand pressure differences in the atmosphere
Geology – the study of the structure of the earth uses chemistry and physics to understand heat, force and chemical composition of rocks
Biology- the study of living things uses chemistry and physics to understand the chemical reactions in plants and animals and physics to study how living things move.

8. What are the “steps” of the Scientific Method?
The scientific method are the ways in which scientists answer questions and solve problems.
Observation
Ask a question
Form a hypothesis
Test the hypothesis
Analyze results
Draw conclusions
Communicate results

9. Steps of the Scientific Method
1) Observation
The use of the senses to gather information.
Qualitative – color, odor, taste, etc.
Quantitative – measurements.
Instruments used:
Rulers, balances, stopwatches, etc.

10. Steps of the Scientific Method
2) Ask a question
3) Hypothesis
An explanation that is based on prior scientific research or observations and can be tested.
If – then statement.

11. Steps of the Scientific Method
4) Testing the Hypothesis – Experiment
A controlled experiment compares the results from a control group with the results from the experimental groups. The groups are exactly the same except for one factor. That factor is the variable.
Independent variable is the variable you change.
Ex. Time
Dependent variable changes in response to the independent variable.
Ex. Distance

12. Steps of the Scientific Method
5) Collect, Record, and Analyze Data
Data is the information gathered through your experiment.
All information needs to be recorded in a notebook, in a data table or other recording devices.
Organizing material makes analyzing the data easier.

13. Steps of the Scientific Method
6) At the end of the investigation, you draw your conclusion.
Accept or reject
Change your hypothesis and retest.
7) Communicate results
How can you do that?

14. A gardener decided he wanted to try a fertilizer for his tomato plants
A gardener decided he wanted to try a fertilizer for his tomato plants. He put fertilizer is 20 plants and called them group A . He just put regular soil into 20 plants and called them group B. Both groups received the same amount of sun light exposure, water, and were exposed to the same temperatures. He found that plants in group A produced an average of 25 kgs of tomatoes where plants in group B produced an average of 15 kgs of tomatoes.
State the hypothesis of the experiment:
State the independent variable, the one you changed:
State the dependent variable, the one that changed because of the experiment:
Which was the control group?
What variables were controlled?
6. State a conclusion for the above experiment:

15. Theory vs. Law
A theory is an explanation for many hypotheses and observations.
Supported many times.
Can predict future results.
Can not be proven 100%
Examples
Big Bang Theory
Einstein’s Theory of Relativity
A law is a summary of many experimental results and observations.
Laws are always true and do not change.
Examples
Newton’s Laws of Gravity
Conservation of Mass

16. Measurements Length Volume Mass Temperature Density Time Meters Liters
Kilogram
Temperature
Kelvin or Celcius
Density
g/cm3
Time
seconds

17. Metric Measurements Prefixes
Symbol
Factor of Base Unit
kilo- K
1,000
hecto- H
100
deka- D 10
BASE
m, L, g, s
Meter, liter, gram, second
deci- d
0.1
centi- c
0.01
milli- m
0.001

18. Metric Conversions K H D __ d c m
1378 millimeters = ________ dekameters
45 centimeters = ________ decimeters
4 liters = ________ hectoliters
5 kilograms = ________ grams

19. Scientific Notation 12345 = 1.2345 x 104 0.00456 = 4.56 x 10-3
A way to express very small or very large numbers
Example:
12345 = x 104
= 4.56 x 10-3
Exponent – the # of times the decimal was moved
(+) to the left
(-) to the right
Coefficient – must be between 1 and 9
Base

20. Scientific Notation
56934 =
1280 = = =

21. Scientific Notation Reverse it! (+) right (-) left 2.347 x 10-3 =