Grade 9 · CAPS
Grade 9 Molecular Structure
Natural Sciences and Technology practice questions with answers
Grade 9 Molecular Structure is part of the CAPS Natural Sciences and Technology curriculum, covering how atoms bond together to form molecules and how chemical formulae describe that structure. Learners identify atoms as the smallest unit of an element, count the atoms represented in a chemical formula, and work with diatomic molecules and the forces (chemical bonds) that hold atoms together.
The practice questions below are drawn from ReClass's own question bank, based on real Grade 9 CAPS assessments, so learners can check their understanding of molecular structure against the kind of questions used in an actual test.
Worked example
4.2 Study the diagram below and answer the questions that follow.
4.2.1 Which diagram, A, B, or C, represents a diatomic molecule? Give a reason for your answer.
Answer & explanation
A , due to the bonding of two atoms of the same element.
You'll also practise
- 1.3 In the diagrams below, hydrogen atoms are represented by white circles, and oxygen atoms are represented by black circles. Which of the diagrams best represents water?
- Choose an item from COLUMN B that matches a statement in COLUMN A. Write only the letter (A – I) next to the question numbers (3.1 to 3.6) in the space provided: 3.1 Diatomic molecule
- The correct chemical formula for sulphur trioxide is:
- What term describes what happens when two atoms combine to form a molecule?
- What is the total number of atoms contained in 5NaHCO3?
- The forces that hold atoms together are called …
- The prefix "di" in the word "diatomic molecule" means …
- Give the correct term: the smallest unit that makes up an element.
- Give the correct term: the smallest of the three subatomic particles, which is negatively charged and located outside the nucleus.
- The smallest particles that make up matter are known as …
- Methane (CH4) reacts completely with oxygen gas (O2) to form carbon dioxide (CO2) and water (H2O). Write the balanced chemical equation for this reaction.
- Sodium (Na) reacts with oxygen gas (O2) to form sodium oxide (Na2O). Write the balanced chemical equation for this reaction.
Common mistakes
- Miscounting the total number of atoms in a formula with a coefficient, e.g. 5NaHCO3.
- Confusing an atom with a molecule.
- Forgetting that "di" in a molecule's name means two atoms, not two molecules.
Aligned to CAPS Grade 9 Natural Sciences and Technology — Molecular Structure.
Check your own understanding
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