Edexcel A-Level Chemistry Paper 1, June 2022: Question 1

7 marks · Medium difficulty · Short Open Response

Complete properties of subatomic particles, identify evidence from atomic emission spectroscopy, draw a p orbital, and explain melting temperatures of silicon and chlorine in terms of structure and bonding.

Practise this question

Question

Question 1 covers atomic structure and the periodic table, containing four parts. Part (a) asks to complete a table of relative charges and masses for a neutron and an electron, given the proton values. Part (b) is a multiple-choice question on what atomic emission spectroscopy provides evidence for, with options A to D. Part (c) asks to draw the shape of a p orbital. Part (d) gives a table of melting temperatures for silicon (1683 K) and chlorine (172 K) and asks to explain the difference in terms of structure and bonding.
Question text

1 This question is about atomic structure and the Periodic Table.

(a) Complete the table to show the relative charges and masses for a neutron and

an electron.

(2)

Particle Relative charge Relative mass

proton +1 1

neutron

electron

(b) Atomic emission spectroscopy provides evidence for the existence of

(1)

A atoms

B electrons

C isotopes

D quantum shells

(c) Draw the shape of a p orbital.

(1)

(d) The melting temperatures of two elements in Period 3 are given in the table.

Element silicon chlorine

Melting temperature / K 1683 172

Explain, in terms of the structure and bonding of each element, the difference

between these values.

(3)

… *P67093RA0232*

(Total for Question 1 = 7 marks)

Mark scheme

Show the mark scheme The mark scheme provides answers for Question 1. Part (a) awards marks for correct relative charges (0 for neutron, -1 for electron) and masses (1 for neutron, 1/1840 or similar for electron). Part (b) gives D (quantum shells) as the correct answer. Part (c) requires a dumbbell-shaped diagram representing a p orbital. Part (d) awards 3 marks: one for stating silicon is giant covalent with strong covalent bonds, one for stating chlorine is simple molecular with weak London forces, and one for comparing the energy required to break these bonds/forces.

Question

Answer Additional Guidance Mark

Number

1(a) Example of table (2)

• any two or three values correct (1)

Particle Relative charge Relative mass

• all four values correct (1) proton (+1) (1)

neutron 0 / no charge 1

electron −1 1/1840

Allow negligible / very small or words to that effect /

values in a range from 1/1800 to 1/2000 (0.0005) for the

relative mass of electron

Do not award 0 / none for mass of electron

Ignore + sign for neutron

Question Answer Mark

number

1(b) (1)

The only correct answer is D (quantum shells)

A is incorrect because atomic emission spectroscopy does not provide evidence for the existence of atoms

B is incorrect because atomic emission spectroscopy does not provide evidence for the existence of electrons

C is incorrect because evidence for isotopes is provided by mass spectrometry

Question

Answer Additional Guidance Mark

Number

1(c) Example of diagram (1)

• diagram of a p orbital

Allow any orientation of p orbital

Ignore axes

Question

Answer Additional Guidance Mark

Number

1(d) An explanation that makes (3)

reference to the following points:

• silicon – giant atomic / giant Do not allow just ‘silicon is a covalent molecule’

covalent / giant molecular / Do not allow reference to ions or metallic bonding

macromolecular

and

contains covalent bonds (1)

• chlorine - (simple) molecular /

molecules / diatomic / Cl2

and

contains London forces (1) Allow dispersion forces / van der Waals’ / attractions between

temporary dipole and induced dipole/ attractions between

instantaneous dipole (- induced dipole) for London forces

• (covalent) bonds in silicon are Do not award covalent bonds being broken in chlorine

stronger than London forces/

intermolecular forces in

chlorine

or

covalent bonds take more

energy to break than London

forces / intermolecular forces

(1) Ignore silicone for silicon as correct spelling is given in the paper

(Total for Question 1 = 7 marks)

How to answer it

Atomic Structure and the Periodic Table

What this question tests:

Core foundational recall of subatomic particles, atomic emission spectra evidence for quantum shells, shapes of atomic orbitals (p-orbital), and linking Period 3 physical properties (melting temperatures) to structure and bonding types.

Part (a) — Subatomic Particles

Relative Charges and Masses

✅ Correct Answer

  • Neutron: Relative charge = 0 (or no charge), Relative mass = 1
  • Electron: Relative charge = -1 , Relative mass = 1/1840 (or 0.0005, negligible, very small)

❌ Common Errors

  • Writing 0 or none for the mass of an electron (it has a tiny mass, approx 1/1840).
  • Including a plus sign or negative sign on the neutral neutron charge.
Mark breakdown (2 marks): 1 mark for any 2 or 3 values correct; 1 mark for all 4 values correct.
Part (b) — Atomic Emission Spectroscopy

Evidence from Spectra

✅ Correct Answer

D (quantum shells)

💡 Key Knowledge

Line emission spectra consist of discrete frequencies of light emitted when electrons drop from higher energy levels to lower ones. Because these energy transitions are fixed (quantised), they prove electrons exist in specific quantum shells (or energy levels).

Mark breakdown (1 mark): 1 mark for selecting option D.
Part (c) — Orbital Shapes

Shape of a p-Orbital

✅ Correct Answer

A dumbbell-shaped (or figure-of-eight) orbital drawn clearly. Any orientation (px, py, or pz) is accepted.

🧠 Exam Technique

Keep your sketches simple and symmetrical. Make sure the lobes are clearly pinched in the middle. Examiners ignore axes, so just focus on drawing a clean dumbbell shape!

Mark breakdown (1 mark): 1 mark for a recognizable diagram of a p-orbital.
Part (d) — Period 3 Melting Temperatures

Silicon vs. Chlorine Structure and Bonding

💡 Key Knowledge & Marking Points

  • Silicon structure: Giant covalent / giant atomic / macromolecular structure containing strong covalent bonds.
  • Chlorine structure: Simple molecular structure (diatomic molecules, Cl₂ ) held together by weak London forces (intermolecular forces).
  • Comparative energy: The covalent bonds in silicon are much stronger / require more energy to break than the weak London forces between chlorine molecules.

❌ Common Errors

  • Calling silicon a "covalent molecule" (it is a giant structure, not molecular!).
  • Stating that covalent bonds are broken inside the chlorine molecules during melting (melting simple molecules breaks intermolecular forces, not covalent bonds).
  • Incorrect terminology like "silicone" instead of silicon.
Mark breakdown (3 marks): 1 mark for silicon bonding/structure, 1 mark for chlorine bonding/structure, and 1 mark for explicitly comparing the relative strengths/energies required to overcome them.

Topics

Physical Chemistry · Inorganic Chemistry · Topic 1: Atomic Structure and the Periodic Table · Topic 2: Bonding and Structure

Question and mark scheme from the Edexcel A-Level Chemistry examination, Paper 1, June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.