Composition of Matter

Grade 5 · General Science

Semester 2 | Period 5 | Week 27

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Subject: General Science

Semester: 2

Period: 5

Week: 27

School Name:
Teacher’s Name:
Subject: General science
Grade Level: Grade 5
Date: Week 27
Lesson Duration: 45 minutes
Week & Period: Week 27, Period 5
Topic: Composition of Matter
Sub-topic: Atoms

Learning Objectives
By the end of the lesson, students should be able to:

  1. Define an atom.
  2. Identify the parts of an atom: protons, neutrons, and electrons.
  3. Explain atomic number and mass number in simple terms.
  4. State how atoms form the basis of matter.

Previous Knowledge
Students already know that matter is made up of particles called atoms and molecules.

Instructional Materials
Chart of atomic structure, model of an atom (ball-and-stick model or diagram), chalk, coins for demonstration.

Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Teacher draws a simple circle with smaller circles inside on the board and asks learners: What do you think this represents?

B – Building Knowledge (Main Lesson Body)
Time: 25–30 minutes

Learners’ Activities (Expanded):

  1. Introduction and Discussion:
  • Teacher introduces the topic: “Everything around us is made of matter. The smallest piece of matter that still has the properties of an element is called an atom.”
  • Learners discuss in pairs what they think an atom is.
  1. Definition and Explanation:
  • Teacher explains: An atom is the smallest unit of matter that retains the properties of an element.
  • Learners are shown diagrams of a simple atom: nucleus in the center, electrons orbiting around it.
  1. Structure of an Atom – Subatomic Particles:
  • Protons: Positively charged particles in the nucleus.
  • Neutrons: Neutral particles (no charge) in the nucleus.
  • Electrons: Negatively charged particles moving in orbits around the nucleus.
  • Teacher explains atomic number: the number of protons in an atom.
  • Teacher explains mass number: sum of protons and neutrons.
  1. Practical Activity – Model of an Atom:
  • Use coins, small balls, or beads:
    • Stack two different colored balls to represent protons and neutrons (nucleus).
    • Use smaller beads or balls on strings to represent electrons orbiting the nucleus.
  • Learners make their own simple atom models in groups and identify protons, neutrons, and electrons.
  1. Examples to Reinforce Learning:
  • Hydrogen atom: 1 proton, 0 neutron, 1 electron
  • Helium atom: 2 protons, 2 neutrons, 2 electrons
  • Oxygen atom: 8 protons, 8 neutrons, 8 electrons
  1. Discussion of Molecules:
  • Teacher explains that atoms combine to form molecules.
  • Simple examples: H₂O (water), O₂ (oxygen gas), CO₂ (carbon dioxide).

Assessment Checks:

  • Teacher asks:
    • “What is an atom?”
    • “Name the three main parts of an atom.”
    • “What does the atomic number represent?”
  • Learners identify protons, neutrons, and electrons from diagrams or their models.
  • Mini quiz: Show an element (e.g., carbon) and ask learners to write its number of protons, neutrons, and electrons.

Notes (Expanded & Detailed):

  • Atom: Smallest unit of matter that still retains the properties of an element.
  • Subatomic Particles:
    • Protons (+): Found in the nucleus, determine atomic number.
    • Neutrons (0): Found in nucleus, add to mass number.
    • Electrons (–): Orbit nucleus, involved in chemical bonding.
  • Atomic Number: Number of protons in the atom; determines the element.
  • Mass Number: Sum of protons and neutrons in the atom.
  • Importance: Atoms combine to form molecules, which make up all matter in the universe.

Homework/Assignment:

  • Draw a simple diagram of a helium atom, label protons, neutrons, and electrons.
  • Write the atomic number and mass number of helium.
  • Identify one atom at home (from any element) and describe its protons, neutrons, and electrons.

C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes
Summary: Teacher summarizes that atoms are the building blocks of matter, made up of protons, neutrons, and electrons. Learners restate the three parts of an atom.

Evaluation Method (Expanded):
Exit slip/quiz: Learners answer: 1. Define atom. 2. Name the three main parts of an atom. 3. What is the atomic number? Teacher collects slips and provides oral feedback.

Assignment (Expanded): Learners should draw and label a diagram of an atom showing protons, neutrons, and electrons.

Follow-up Activity: Learners will look up one element in the periodic table and write down its atomic number and mass number.

Differentiation / Inclusive Strategies
Teacher uses diagrams, models, and hands-on activities to aid understanding. Learners who find abstract concepts difficult will work with physical objects to represent protons, neutrons, and electrons. Stronger learners may be asked to explain simple relationships between atomic number and element identity.

Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low