Chemistry Unit 01: Scientific Method Notes

The scientific method is a logical approach to solving problems by ...

• observing and collecting data

• formulating hypotheses

• testing hypotheses

• formulating theories that are supported by data

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What is the Scientific Method?​

Step 1: Observing is the use of the senses to obtain information/data.

• data may be

  • qualitative (descriptive)

  • quantitative (numerical)

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Observing and Collecting Data

A system is a specific portion of matter in a given region of space that has been selected for study during an experiment or observation.

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What are we observing?

Step 2: Scientists make generalizations based on the data.

• Scientists use generalizations about the data to formulate a hypothesis, or testable statement.

  • Hypotheses are often “if-then” statements.

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Formulating Hypotheses

Step 3: Testing a hypothesis requires experimentation that provides data to support or refute a hypothesis or theory.

• Controls are the experimental conditions that remain constant.

• Variables are any experimental conditions that change.

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Testing Hypotheses

Step 4: A model in science is more than a physical object...

• a model is often an explanation of how phenomena occur and how data or events are related.

  • visual, verbal, or mathematical

    • example: atomic model of matter

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Theorizing

A theory is a broad generalization that explains a

body of facts or phenomena.

• example: atomic theory​

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What is a theory?

A scientific law is different from a theory. Laws describe patterns or relationships in nature (these typically do not change), while a theory explains why the action takes place and is backed by evidence.

What is a theory?
Continued...

Law: Newton's laws of gravity describe mathematically how this happens and tells us how gravity acts between objects.

Example:

Theory: Einstein's theory of relativity explains why gravity occurs. According to this theory, the Earth bends space and time, and the apple follows that curved space/time toward the ground.