Scientific Method Steps and Measurement Units for Physical Science

Scientific Method: Steps and Definitions

Describe each step of the Scientific Method.

Purpose

Ask a question. A clear, testable question defines the focus of investigation.

Hypothesis

Hypothesis: This is an educated guess about what you expect will happen. It should be stated as a testable prediction.

Experiment

Experiment: Design and perform an experiment to test your hypothesis. Include controls and clearly defined variables.

Collect Data

Collect data: Record observations and analyze what the data means. Often you'll prepare a table or graph of the data.

Conclusion

Conclusion: Decide whether to accept or reject your hypothesis. Communicate your results clearly.

Common Measurement Units and Examples

Units (common): Volume: cm³; Length: m, cm; Mass: kg, g, mg; Temperature: °C or °F.

Task: 5 examples of each (be able to identify which unit is used when an example is given).

Volume

Volume: When measuring the volume of a rectangular prism, multiply the length × width × height.

Length

Length: We can measure how long things are, how tall they are, or how far apart they are. Those are all examples of length measurements.

Mass

Mass: When you measure the amount of matter in an object. Example discussion: If we could move the same object—such as a ten-pound bowling ball (whose mass is about 7.5 kg based on industry standards for a regulation ball)—to each planet in our solar system, its mass would remain the same but its weight would change due to different gravitational forces.

Temperature

Temperature: Used to find out how hot or cold something is. Common scales are Celsius (°C) and Fahrenheit (°F).

Mass and Weight Notes

Mass: measured in kilograms (kg). Weight: measured in newtons (N).

100 g ≈ 0.98 N on Earth (since 100 g = 0.100 kg and weight = mass × g, where g ≈ 9.81 m/s²).

Physical Science and Its Areas

Physical science is the systematic study of the inorganic world, distinct from the study of the organic world (the province of biological science). Physical science is ordinarily thought of as consisting of four broad areas: astronomy, physics, chemistry, and the Earth sciences. Each of these is divided into fields and subfields. This article discusses the historical development—with attention to the scope, principal concerns, and methods—of the first three areas. The Earth sciences are discussed in a separate article.

Physical Properties

Physical properties: Properties that can be detected just by using the senses or measured without changing the composition of the substance (for example: color, odor, density, melting point, and boiling point).

Branches, Professions, and Relationships

Name 3 other branches of Physical Science and how they are related to it:

• Chemistry: The study of matter, its properties, and how it changes—closely related to physical science because it explains material behavior and reactions.
• Physics: The study of matter and energy and the interactions between them—fundamental to understanding forces, motion, and energy transfer in physical science.
• Organic Chemistry: The branch of chemistry focused on carbon-containing compounds; it connects to physical science through chemical principles and measurements used to study organic materials.

Definitions (roles): Chemist: an expert in chemistry or a person engaged in chemical research or experiments. Physicist: an expert in or student of physics.

Thermal Conductivity

Thermal conductivity: The measure of a material's ability to allow heat to flow from its warmer surface through the material to its colder surface.