Secondary 3 Chemistry Atomic Structure Bonding Quiz

Secondary 3 Chemistry Quiz - Atomic Structure Bonding

Name: ___________________________
Class: ___________________________
Date: ___________________________
Score: _______ / 40

Duration: 50 minutes
Total Marks: 40

Instructions:

• Answer all 20 questions.
• Section A: Multiple-choice style short items (1 mark each).
• Section B: Structured short answers (2 marks each).
• Section C: Extended response (3–4 marks each).
• Write your answers clearly in the spaces provided.
• Use proper chemical notation where needed.

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Section A (Questions 1–5, 1 mark each)

1. An atom of element X has 11 protons and 12 neutrons. What is its nucleon number? [1]
Answer: __________

2. Which sub-atomic particle has a relative charge of –1 and negligible mass? [1]
Answer: __________

3. Which type of bonding is present in a sample of magnesium metal? [1]
Answer: __________

4. Dot-and-cross diagrams are most commonly used to show the formation of which type of bond? [1]
Answer: __________

5. An isotope of chlorine has 17 protons and 18 neutrons. What is its mass number? [1]
Answer: __________

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Section B (Questions 6–15, 2 marks each)

6. Element aluminium has atomic number 13. Write the electron configuration of a neutral aluminium atom. [2]
Answer: __________

7. A sodium atom forms a Na⁺ ion. State the number of electrons lost and write the electron configuration of Na⁺. [2]
Answer: __________

8. Draw a dot-and-cross diagram to show the formation of magnesium chloride (MgCl₂) from Mg and Cl atoms. Show only outer shell electrons. [2]
Answer: (draw in space below)

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9. Oxygen molecule (O₂) is held by a covalent bond. Explain what is meant by "electron sharing" in this context. [2]
Answer: __________

10. State two physical properties of ionic compounds and briefly explain each using bonding ideas. [2]
Answer: __________

11. Diamond and graphite are both forms of carbon. State one structural difference and link it to a property. [2]
Answer: __________

12. A compound is formed between potassium (metal) and oxygen (non-metal). Predict the type of bonding and give a reason. [2]
Answer: __________

13. Chlorine has two common isotopes: Cl-35 (75%) and Cl-37 (25%). Calculate the relative atomic mass of chlorine. [2]
Answer: __________

14. State the charge of the following ions: (a) oxide ion, (b) aluminium ion. [2]
Answer: (a) ______ (b) ______

15. Explain why metals are good conductors of electricity using the "sea of electrons" model. [2]
Answer: __________

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Section C (Questions 16–20, 3–4 marks each)

16. Compound A is formed between sodium and chlorine.
(a) Predict the type of bonding in A. [1]
(b) Explain your answer in terms of electronegativity. [2]
(c) Predict one physical property of A based on its bonding. [1]
Answer:
(a) __________
(b) __________
(c) __________

17. The diagram below shows the arrangement of particles in three states of matter.

Generated diagram for Q17.

Using kinetic particle theory, describe the arrangement and movement of particles in the liquid state and explain how diffusion occurs in gases. [4]
Answer: __________

18. A student is given a dot-and-cross diagram of a molecule of methane (CH₄).
(a) State the type of bonding in methane. [1]
(b) Explain why methane has a low melting point compared to sodium chloride. [3]
Answer:
(a) __________
(b) __________

19. Compare the structure of diamond and graphite. Include how the bonding leads to their uses. [4]
Answer: __________

20. An atom has the symbol $^{40}_{20}Ca$.
(a) State the number of protons, neutrons, and electrons. [2]
(b) Write the electron configuration. [1]
(c) Would Ca form a cation or anion? Give reason. [1]
Answer:
(a) Protons: ____ Neutrons: ____ Electrons: ____
(b) __________
(c) __________