SCIENCE

General Science Grade 8 Study Guide
Table of Contents

  1. Basics of Scientific Investigation

    • Scientific Measurements

    • Doing Scientific Investigation

    • Review Exercise

  2. Composition of Matter

    • Early Thinking about the Composition of Matter

    • Inside of an Atom

    • Molecules

    • Review Exercise

  3. Classification of Compounds

    • Introduction

    • Organic Compounds

    • Inorganic Compounds

    • Neutralization Reaction and Salts

    • Review Exercise

  4. Human Body Systems and Health

    • Integumentary System

    • Muscular System

    • Skeletal System

    • Digestive System

    • Respiratory System

    • Circulatory System

    • Reproductive System

    • Review Exercise

  5. Ecosystem and Conservation of Natural Resources

    • Ecosystem and Interactions

    • Food Chain and Food Web

    • Nutrient Cycles and Energy Flow

    • Conservation of Natural Resources

    • Review Exercise

  6. The Solar System

    • Family of the Solar System

    • Formation of the Solar System

    • Earth in Comparison with Solar System

    • Review Exercise

  7. Physical Phenomena in the Surrounding

    • Phenomena of Light

    • Vision and Imaging

    • Sound

    • Heat

    • Magnetism

    • Review Exercise

Unit 1: Basics of Scientific Investigation

Learning Outcomes:

At the end of this unit, you will be able to:

  • Identify the basic and derived units of measurements in various systems, including the metric and imperial systems.

  • Explain the concept of measuring physical quantities, such as mass, volume, and temperature, using appropriate tools (e.g., scales, graduated cylinders, thermometers).

  • Describe the key components of a scientific investigation, including the formulation of hypotheses, experimental design, and data analysis.

  • Demonstrate the ability to work effectively and respectfully with others in performing fair testing, including proper collaboration techniques and communication skills.

1.1 Scientific Measurements

  • Measurement: Process of obtaining the magnitude of a quantity relative to an agreed standard (e.g., meter for length, kilogram for mass).

  • Indigenous Methods: Locally practiced measurement methodologies that may not conform to modern scientific standards, often based on practical experiences (e.g., using body parts for measuring length).

  • Modern Methods: Measurements that are widely accepted in the scientific community, including standard units and sophisticated instruments.

Measurements Classifications:

  • Fundamental Quantities: Quantities that can’t be expressed in terms of other quantities. Examples: length, mass, time, temperature, electric current.

  • Derived Quantities: Quantities that depend on fundamental quantities, often calculated using formulas. Examples: speed (length/time), area (length × length), density (mass/volume).

1.2 Doing Scientific Investigation

  • Components of Scientific Investigation: Each investigation generally includes:

    • Observing: Gathering initial data through careful observation of phenomena.

    • Hypothesizing: Formulating a testable and falsifiable hypothesis based on observations.

    • Experimenting: Designing and conducting experiments to test the hypothesis, ensuring controlled and variable conditions are clearly defined.

    • Analyzing: Interpreting data using statistical tools to determine the validity of the results.

    • Concluding: Drawing conclusions from the analysis and discussing implications or further questions raised by the investigation.

  • Ethical Issues: Considerations regarding the rights of participants, environmental impacts, and the integrity of data in scientific investigations. Ethical practices must be followed to avoid bias and promote sustainability.

Review Exercise

  • Identify various indigenous methods of measurement and discuss their relevance in modern science.

  • State the difference between accuracy (closeness to true value) and precision (consistency of measurements).