A Level H2 Chemistry Atomic Structure Bonding Quiz

A-Level Chemistry H2 Quiz - Atomic Structure Bonding

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

Duration: 60 minutes
Total Marks: 40

Instructions:

• Answer all 20 questions.
• Section A: Multiple-choice style short items (1–5).
• Section B: Structured short-answer questions (6–15).
• Section C: Data interpretation and extended response (16–20).
• Show all working where calculations are required.
• Use the Data Booklet where relevant.

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

1. An atom of isotope (^{37}{17}\text{Cl}) contains 20 neutrons. How many electrons does a neutral atom of (^{35}{17}\text{Cl}) have?

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2. Which type of orbital has a dumbbell shape?
   A. s
   B. p
   C. d
   D. f

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3. The first ionisation energy is defined as the energy required to remove one electron from ______________ in the gaseous state.

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4. In a σ (sigma) bond formed by overlap of two s orbitals, the electron density lies ________________________ the nuclei.

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5. Which intermolecular force is present between all molecules, polar or non-polar?
   A. Hydrogen bonding
   B. Permanent dipole–dipole
   C. Induced dipole–induced dipole
   D. Ionic bonding

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Section B (Questions 6–15, marks as stated, Total 20 marks)

6. [2 marks] Deduce the numbers of protons, neutrons, and electrons in the ion (^{27}\text{Al}^{3+}).
   Protons: _______
   Neutrons: _______
   Electrons: _______

7. [2 marks] Write the full electronic configuration of a neutral nitrogen atom (Z = 7).

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8. [2 marks] State the shape and bond angle of (\text{BF}_3) according to VSEPR theory.
   Shape: ________________________
   Bond angle: ________________________

9. [2 marks] Draw a dot-and-cross diagram for (\text{CO}_2). Show only outer-shell electrons of C and O.

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10. [2 marks] Explain why (\text{NH}_3) (ammonia) is a polar molecule although it contains polar N–H bonds.

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11. [2 marks] Describe the bonding in metallic sodium.

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12. [2 marks] State the type of bonding present in solid (\text{MgO}) and name the particles responsible for electrical conductivity in the molten state.
    Bonding: ________________________
    Conducting particles: ________________________

13. [2 marks] Compare the boiling points of (\text{H}_2\text{O}) and (\text{H}_2\text{S}). Explain your answer with reference to intermolecular forces.

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14. [2 marks] The bond energy of C–C is approximately 347 kJ mol⁻¹ and C=C is 614 kJ mol⁻¹. Which bond is shorter? Explain.

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15. [2 marks] Deduce whether (\text{CCl}_4) is polar or non-polar. Use bond polarity and molecular shape in your answer.

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Section C (Questions 16–20, marks as stated, Total 15 marks)

16. [3 marks] The successive ionisation energies (kJ mol⁻¹) of element X are:
    1st: 738, 2nd: 1451, 3rd: 7733, 4th: 10540.
    (a) Deduce the group of X in the Periodic Table.
    (b) Write the formula of the ion formed when X loses its valence electrons.
    (a) ________________________
    (b) ________________________

17. [3 marks] Given the following electronegativity values: H = 2.1, Cl = 3.0, C = 2.5, O = 3.5.
    (a) Which bond is most polar: C–H, C–Cl, or C–O?
    (b) State the direction of the dipole in C–O (show δ+ and δ–).
    (a) ________________________
    (b) ________________________

18. [3 marks] The table shows melting points of four substances.

Explain why substance C has a much higher melting point than substance A.  
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19. [3 marks] Describe how a dative (coordinate) bond is formed in (\text{NH}_4^+). Include the origin of the electron pair.
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20. [3 marks] The first ionisation energies of Ne, Na, and Mg are 2081, 496, and 738 kJ mol⁻¹ respectively. Explain the trend from Ne to Na to Mg in terms of nuclear charge and electron shielding.

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