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O Level Chemistry Periodic Table Quiz

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O Level Chemistry From Real Exams Generated by Qwen3.6 Plus Updated 2026-08-17

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Questions

O-Level Chemistry Quiz - Periodic Table

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

Duration: 45 minutes
Total Marks: 40

Instructions:

Answer all questions.
Write your answers in the spaces provided.
The number of marks is given in brackets [ ] at the end of each question or part question.
A copy of the Periodic Table is provided on the last page of this quiz (not included here, assume standard access).

Section A: Multiple Choice Questions (10 Marks)

1. Which statement about the elements in Group I of the Periodic Table is correct? A. They become less reactive as you go down the group. B. They form ions with a charge of 1+. C. They have high melting points. D. They are non-metals.

[ ]

2. Element X is in Group 17 and Period 3 of the Periodic Table. Which statement about element X is correct? A. It is a solid at room temperature. B. It forms an ion with a charge of 1+. C. It has 7 electrons in its outer shell. D. It reacts with water to form an alkaline solution.

[ ]

3. Which property is characteristic of transition elements? A. Low density B. Low melting point C. Formation of coloured compounds D. Softness

[ ]

4. The table shows the properties of four elements.

Element	Melting Point (°C)	Electrical Conductivity	Reaction with Water
A	-101	Poor	Reacts violently
B	98	Good	Reacts steadily
C	1535	Good	No reaction
D	-189	Poor	No reaction

Which element is likely to be a transition metal? A. A B. B C. C D. D

[ ]

5. Why are noble gases unreactive? A. They have a full outer shell of electrons. B. They have low boiling points. C. They are all gases at room temperature. D. They have high ionisation energies.

[ ]

6. Which equation represents the reaction between potassium and water? A. $2K + H_2O \rightarrow K_2O + H_2$ B. $2K + 2H_2O \rightarrow 2KOH + H_2$ C. $K + H_2O \rightarrow KOH + H$ D. $2K + 2H_2O \rightarrow 2KOH + O_2$

[ ]

7. Chlorine gas is bubbled through aqueous potassium iodide. What is observed? A. The solution remains colourless. B. The solution turns brown. C. A white precipitate forms. D. Effervescence occurs.

[ ]

8. Which statement explains why lithium, sodium, and potassium are in the same group of the Periodic Table? A. They have the same number of electron shells. B. They have the same number of protons. C. They have the same number of electrons in their outer shell. D. They have similar atomic masses.

[ ]

9. An element has the electronic configuration 2, 8, 18, 7. In which group and period is this element found? A. Group 7, Period 4 B. Group 17, Period 4 C. Group 7, Period 3 D. Group 17, Period 3

[ ]

10. Which oxide is amphoteric? A. $MgO$ B. $Al_2O_3$ C. $SO_2$ D. $Na_2O$

[ ]

Section B: Structured Questions (30 Marks)

11. The diagram below shows a section of the Periodic Table.

Image pending generation for this question.

	Group 1	Group 2	...	Group 17	Group 18
Period 2	Li	Be	...	F	Ne
Period 3	Na	Mg	...	Cl	Ar

(a) Identify the element that is a noble gas. _________________________________________________________________________ [1]

(b) Identify the element that reacts most vigorously with water. _________________________________________________________________________ [1]

(c) Identify the element that forms a diatomic molecule with a single covalent bond. _________________________________________________________________________ [1]

(d) Explain why fluorine is more reactive than chlorine.

_________________________________________________________________________ [2]

12. Iron is a transition element. Sodium is a Group I element. Compare the physical and chemical properties of iron and sodium. Complete the table below.

Property	Iron (Transition Element)	Sodium (Group I Element)
Melting Point	High	(a) ____________________ [1]
Density	High	(b) ____________________ [1]
Colour of Compounds	(c) ____________________ [1]	Usually white/colourless
Catalytic Activity	(d) ____________________ [1]	None

13. A student investigates the reactions of Group I metals with water. (a) Describe the observation when sodium reacts with water.

_________________________________________________________________________ [2]

(b) The reaction of potassium with water is more vigorous than that of sodium. Explain this difference in reactivity in terms of atomic structure.

_________________________________________________________________________ [3]

(c) Write a balanced chemical equation for the reaction between lithium and water. _________________________________________________________________________ [2]

14. Chlorine, bromine, and iodine are halogens (Group 17). (a) State the trend in colour down Group 17. _________________________________________________________________________ [1]

(b) State the physical state of bromine at room temperature and pressure. _________________________________________________________________________ [1]

(c) Aqueous chlorine is added to aqueous potassium bromide. (i) Write the ionic equation for this reaction. _________________________________________________________________________ [2]

(ii) Explain why this reaction occurs.

_________________________________________________________________________ [2]

(d) Aqueous iodine is added to aqueous potassium chloride. State what is observed and explain your answer.

_________________________________________________________________________ [2]

15. Element X is in Period 3. Its oxide, $X_2O_3$ , is amphoteric. (a) Identify element X. _________________________________________________________________________ [1]

(b) Define the term amphoteric.

_________________________________________________________________________ [1]

(c) Write balanced chemical equations for the reaction of $X_2O_3$ with: (i) Dilute hydrochloric acid. _________________________________________________________________________ [2]

(ii) Aqueous sodium hydroxide. _________________________________________________________________________ [2]

16. The table below shows some properties of the first three elements in Group 1.

Element	Atomic Radius (nm)	Ionisation Energy (kJ/mol)
Lithium	0.152	520
Sodium	0.186	496
Potassium	0.227	419

(a) Describe the trend in atomic radius down Group 1. _________________________________________________________________________ [1]

(b) Explain the trend in ionisation energy down Group 1.

_________________________________________________________________________ [3]

(c) Predict whether rubidium (below potassium) will have a higher or lower ionisation energy than potassium. Explain your answer.

_________________________________________________________________________ [2]

17. Consider the elements in Period 3: Sodium (Na), Magnesium (Mg), Aluminium (Al), Silicon (Si), Phosphorus (P), Sulfur (S), Chlorine (Cl), Argon (Ar).

(a) Which element in Period 3 has the highest melting point? _________________________________________________________________________ [1]

(b) Explain why the melting point of silicon is very high compared to chlorine.

_________________________________________________________________________ [2]

_________________________________________________________________________ [1]

(d) Explain why argon has the lowest boiling point in Period 3.

_________________________________________________________________________ [1]

18. The reactivity of halogens decreases down Group 17.

(a) Explain this trend in terms of atomic structure and electron gain.

_________________________________________________________________________ [3]

(b) Fluorine is the most reactive halogen. State one safety precaution necessary when handling fluorine gas in a laboratory. _________________________________________________________________________ [1]

(c) Hydrogen reacts with halogens to form hydrogen halides. (i) Write the equation for the reaction between hydrogen and chlorine. _________________________________________________________________________ [1]

(ii) State the observation when hydrogen burns in chlorine. _________________________________________________________________________ [1]

19. Transition metals are widely used in industry.

(a) State two chemical properties characteristic of transition metals, other than catalytic activity.

_________________________________________________________________________ [2]

(b) Iron is extracted from its ore, hematite ( $Fe_2O_3$ ), in a blast furnace using carbon monoxide. (i) Write the equation for the reduction of hematite by carbon monoxide. _________________________________________________________________________ [2]

(ii) Why is carbon monoxide used instead of carbon directly in the main reduction zone? _________________________________________________________________________ [1]

_________________________________________________________________________ [2]

20. The position of an element in the Periodic Table can be deduced from its properties.

Element Q is a soft, silvery-white metal. It reacts vigorously with cold water to produce an alkaline solution and hydrogen gas. It is stored under oil to prevent reaction with air.

(a) To which group of the Periodic Table does Element Q belong? _________________________________________________________________________ [1]

(b) Explain why Element Q is stored under oil.

_________________________________________________________________________ [1]

(c) Element Q has an atomic number of 19. (i) Write the electronic configuration of Element Q. _________________________________________________________________________ [1]

(ii) Deduce the formula of the ion formed by Element Q. _________________________________________________________________________ [1]

(d) Predict how the reactivity of Element Q compares to sodium. Explain your answer.

_________________________________________________________________________ [2]

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Answers

O-Level Chemistry Quiz - Periodic Table (Answer Key)

Total Marks: 40

Section A: Multiple Choice Questions

1. B

Reasoning: Group I elements (alkali metals) lose one electron to form 1+ ions. Reactivity increases down the group, melting points are low, and they are metals.

2. C

Reasoning: Group 17 elements (halogens) have 7 valence electrons. Period 3 halogen is Chlorine (gas, not solid). They form 1- ions. Reaction with water produces acidic solutions (HCl + HOCl).

3. C

Reasoning: Transition elements typically form coloured compounds, have high melting points, high densities, and act as catalysts.

4. C

Reasoning: Transition metals generally have high melting points, good conductivity, and are less reactive with water than Group I/II metals. A is a halogen (Cl), B is Group I (Na/K), D is a noble gas.

5. A

Reasoning: Noble gases have a stable octet (full outer shell), making them chemically inert.

6. B

Reasoning: Alkali metals react with water to form metal hydroxide and hydrogen gas. $2K + 2H_2O \rightarrow 2KOH + H_2$ .

7. B

Reasoning: Chlorine is more reactive than iodine. It displaces iodide ions to form iodine ( $Cl_2 + 2I^- \rightarrow 2Cl^- + I_2$ ). Iodine in solution is brown/yellow-brown.

8. C

Reasoning: Elements in the same group have the same number of valence electrons, leading to similar chemical properties.

9. B

Reasoning: 4 electron shells = Period 4. 7 valence electrons = Group 17.

10. B

Reasoning: Aluminium oxide ( $Al_2O_3$ ) is amphoteric (reacts with both acids and bases). MgO is basic, $SO_2$ is acidic, $Na_2O$ is basic.

Section B: Structured Questions

11. (a) Ne (Neon) [1] (b) Na (Sodium) [1] * Note: Li also reacts, but Na is more vigorous. Between Li and Na, Na is the better answer for "most vigorously" in this specific subset. (c) F (Fluorine) or Cl (Chlorine) [1] * Note: Halogens exist as diatomic molecules ( $F_2, Cl_2$ ) with single covalent bonds. (d) Fluorine has fewer electron shells / smaller atomic radius than chlorine. [1] The attraction between the nucleus and the incoming electron is stronger in fluorine because the outer shell is closer to the nucleus (less shielding). [1]

12. (a) Low [1] (b) Low [1] (c) Coloured (or specific colours like green/blue/yellow) [1] (d) Acts as a catalyst (or has catalytic properties) [1]

13. (a) Any two of: * Floats on water [1] * Moves rapidly/darts on surface [1] * Melts into a sphere [1] * Effervescence/bubbles produced [1] * Max 2 marks. (b) Potassium has more electron shells than sodium. [1] The outer electron is further from the nucleus. [1] There is more shielding from inner shells, so the attraction between the nucleus and the outer electron is weaker. [1] Therefore, the outer electron is lost more easily. (c) $2Li + 2H_2O \rightarrow 2LiOH + H_2$ [2] * 1 mark for correct formulae, 1 mark for balancing.

14. (a) Gets darker [1] * Accept: Pale yellow/green $\rightarrow$ orange/brown $\rightarrow$ grey/black. (b) Liquid [1] (c) (i) $Cl_2 + 2Br^- \rightarrow 2Cl^- + Br_2$ [2] * 1 mark for correct species, 1 mark for balancing/charges. (ii) Chlorine is more reactive than bromine. [1] Chlorine can displace bromine from its halide solution. [1] (d) No observable change / Solution remains brown (colour of iodine). [1] Iodine is less reactive than chlorine. [1] Therefore, iodine cannot displace chloride ions from the solution. [1] * Max 2 marks.

15. (a) Aluminium (Al) [1] (b) An oxide (or hydroxide) that reacts with both acids and bases. [1] (c) (i) $Al_2O_3 + 6HCl \rightarrow 2AlCl_3 + 3H_2O$ [2] * 1 mark for formulae, 1 mark for balancing. (ii) $Al_2O_3 + 2NaOH + 3H_2O \rightarrow 2NaAl(OH)_4$ [2] * Accept: $Al_2O_3 + 2NaOH \rightarrow 2NaAlO_2 + H_2O$ (Sodium aluminate) * 1 mark for formulae, 1 mark for balancing.

16. (a) Atomic radius increases down the group. [1] (b) Down the group, the number of electron shells increases. [1] The outer electron is further from the nucleus. [1] Shielding by inner electrons increases. [1] Therefore, the attraction between the nucleus and the outer electron decreases, requiring less energy to remove it. (c) Lower ionisation energy. [1] Rubidium has more electron shells than potassium, so the outer electron is further from the nucleus and experiences more shielding, making it easier to remove. [1]

17. (a) Silicon (Si) [1] (b) Silicon has a giant covalent (macromolecular) structure. [1] Strong covalent bonds exist between all atoms, requiring a large amount of energy to break. [1] * Chlorine exists as simple molecules with weak intermolecular forces. (c) Electrical conductivity increases. [1] * Na, Mg, Al are metals with delocalised electrons. (d) Argon exists as single atoms (monatomic). [1] It has weak van der Waals forces between atoms, requiring very little energy to overcome. [1]

18. (a) Down the group, atomic radius increases and shielding increases. [1] The attraction between the nucleus and an incoming electron becomes weaker. [1] Therefore, it is harder to gain an electron, so reactivity decreases. [1] (b) Use a fume cupboard / Wear gloves and eye protection. [1] * Fluorine is toxic and highly corrosive. (c) (i) $H_2 + Cl_2 \rightarrow 2HCl$ [1] (ii) Burns with a pale blue flame (or white mist/fumes of HCl formed). [1]

19. (a) Any two: 1. Form coloured compounds/ions. [1] 2. Form ions with different charges (variable oxidation states). [1] (b) (i) $Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2$ [2] * 1 mark for formulae, 1 mark for balancing. (ii) Carbon monoxide is a gas and mixes better with the solid ore, allowing for more efficient contact/reaction. [1] (c) Steel contains atoms of different sizes (carbon/other metals) mixed with iron. [1] These different sized atoms disrupt the regular lattice structure, preventing layers from sliding over each other easily. [1]

20. (a) Group 1 [1] (b) It reacts with oxygen and moisture (water vapour) in the air. [1] * Storing under oil prevents contact with air. (c) (i) 2, 8, 8, 1 [1] (ii) $K^+$ [1] (d) Element Q (Potassium) is more reactive than sodium. [1] Potassium has more electron shells, so the outer electron is further from the nucleus and shielded more. [1] The outer electron is lost more easily. [1]