Secondary - 2018 - Class - 9 & 10 - Chemistry 9 PDF EV

Chemistry Classes Nine-Ten National Curriculum and Textbook Board, Bangladesh

Chapter 1: Concept of Chemistry

• Questions raised by students:

  • What is chemistry?

  • Why should we learn chemistry?

  • Benefits of chemistry?

  • Relation to other branches of science.

Objectives of the Lesson

By the end of the lesson, students will be able to:

• Explain the concept of chemistry.

• Identify the scopes of chemistry.

• Explain the relation of chemistry to other sciences.

• Understand the importance of learning chemistry.

• Describe methods of investigation and research in chemistry.

• Plan investigative tasks, choose hypotheses and conduct experiments.

• Take necessary safety measures while experimenting practically.

• Explain phenomena in the natural and physical world in terms of chemistry.

1.1 Introduction to Chemistry

• Natural Science: Branch of science that aims to understand nature through logic and observation.

• Chemistry focuses on the structure of matter, its nature, and changes.

  • Example: Discusses carbon in coal and its reactions.

• Branches of Natural Science: Physics, chemistry, botany, zoology, microbiology, etc.

• Historical usage of chemistry by humans dates back to prehistoric times, notably in the refinement of metals and creation of compounds.

1.2 Scopes of Chemistry

• Chemistry relates to everything including gases in the air and interactions of elements over time.

  • All living beings are chemical factories with ongoing reactions.

  • Everyday items like clothes and cosmetics are also chemical products.

• Examples of chemical interactions:

  • Breathing: Oxygen reacts with food to produce energy.

  • Drinking water: Involves important ionic reactions.

  • Food production: Utilizes fertilizers and insecticides in agriculture.

1.3 Relationship Between Chemistry and Other Science Branches

1. Relationship with Biology: Photosynthesis is a chemical process that synthesizes glucose.

2. Relationship with Physics: Chemistry relies on energy principles, particularly in battery and fuel applications.

3. Relationship with Mathematics: Mathematical theories underlie chemical measurements and calculations.

1.4 Importance of Studying Chemistry

• Chemistry is omnipresent in daily life:

  • Products used daily (toothpaste, food) are chemical contributions.

  • Advancements in medicine are rooted in chemistry (curing diseases).

• Environmental awareness: Understanding chemical waste effects and how it pollutes air, water, and soil.

1.5 The Process of Research in Chemistry

• Science aims for humanity's betterment; research involves:

  • Finding new knowledge through systematic investigation.

  • Steps include:

    1. Determine the research topic.

    2. Collect and analyze data.

    3. Conduct experiments and document findings.

1.6 Safety Measures in Chemistry Laboratory

• Understand the nature of chemicals the before handling them; utilize appropriate protective gear (apron, gloves, goggles).

• Aware of hazards associated with reactions (corrosive, flammable substances).

• Labels help identify risks and precautions necessary.

Elementary Concepts

• Acid and Base Neutralization: pH understanding; acids lower pH while bases raise it.

• Environmental significance: Protecting from pollutants like carbon dioxide and sulphur compounds.

1.7 Summary

• Chemistry links closely to daily life and myriad of scientific disciplines, indicating its foundational role in understanding and benefiting society.