1. Ms. Hirsh Physical Science
What is Science?
Ms. Hirsh
Physical Science

2. Scientific Method (5 Steps)
An organized plan for gathering, organizing and communicating information
Used to solve a problem or better understand an observed event
Observation/Question  Hypothesis  Controlled Experiment  Data Collection  Conclusion

3. Parts to a Good Experiment
Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged or controlled
Controlled Experiment – Only 1 variable
Control – the factors in an experiment that remain the same and do not change
Variable – the factors in a experiment that change. A good experiment only contains 1 variable
Manipulated Variable – Variable that deliberately changes
Responding Variable – Variable that changes in response to the manipulated variable

4. Example Experiment Plants grow best under green light
10 basil plants are started from the seed and grown under various types of light
5 are grown under white light and 5 are grown under green light
After several weeks the plants are measured and the average height of the plants are recorded
What is the variable (the part of the experiment that changes)?
Variable – green light
Manipulating variable – green light
Responding variable - plant growth
What is the control (the parts of the experiment that are kept the same)?
Control – white light, # and type of plants, amount of water, sunlight, temperature, ect.

5. Theory verse Law
As evidence from an investigation builds up, a hypothesis may become so supported that scientists consider it a theory
Hypothesis – scientific testable explanation for an observation or phenomenon
Theory – Well tested explanation for a set of observations
Subject to change, may be revised
Never proved, only disproved
Widely accepted by scientific community
Law – Statement that summarizes a pattern in nature
Law states how something will behave and a theory explains how it works
***REMEMBER*** theories and laws are not absolute, science is always subject to change

6. Branches of Science
Chemistry – composition, structure, properties and reactions of matter
Physics – matter and energy and interactions between the two through forces and motion
Geology – origin, history and structure of earth
Astronomy – universe beyond earth
Biology – origin and behavior of living things
Physical science – physics and chemistry