AQA GCSE Combined Science: Trilogy Chemistry Paper 1 (Foundation), 2023: Question 1

8 marks · Low Demand difficulty · Short Answer

Identify subatomic particles, charges, states of matter, and the historical development of the atomic model.

Practise this question

Question

The image shows a multi-part GCSE science question. Part 01.1 features a diagram of a beryllium atom with 4 protons and 5 neutrons in the nucleus and 4 electrons in shells. Part 01.2 shows a beryllium ion with only 2 electrons. Figure 3 illustrates the three states of matter: A (solid, regular arrangement), B (liquid, random but close), and C (gas, widely spaced). Figure 4 shows three historical atomic models: nuclear, plum pudding, and tiny spheres. Questions ask for particle counts, ion charge, state identification, phase changes, and the chronological order of atomic models.
Question text

01 All substances are made from atoms.

01.1 Figure 1 represents a beryllium atom.

Figure 1

What is the number of protons and the number of neutrons in the beryllium atom?

[2 marks]

Number of protons

Number of neutrons

01.2 Figure 2 represents a beryllium ion.

Figure 2

What is the relative charge on a beryllium ion?

[1 mark]

Tick ( ) one box.

0 +1 +24

Figure 3 shows the arrangement of atoms in the three states of matter.

Figure 3

01.3 What state of matter is represented by state C in Figure 3?

[1 mark]

Tick ( ) one box.

Gas

Liquid

Solid 5

01.4 What is the name of the process when state B changes into state A?

Use Figure 3.

[1 mark]

Tick ( ) one box.

Condensing

Freezing

Melting

01.5 How can state B be changed into state C?

Use Figure 3.

[1 mark]

Experimental evidence led to the scientific model of the atom changing over time.

01.6 Figure 4 shows three models for the atom.

Figure 4

What is the order for the development of the model of the atom?

[1 mark]

Tick ( ) one box.

01.7 Complete the sentence.

Choose the answer from the box.

[1 mark]

Bohr Chadwick Mendeleev

The existence of neutrons was discovered by .

Mark scheme

Show the mark scheme The mark scheme table lists the correct answers for each part of Question 1. 01.1: 4 protons and 5 neutrons. 01.2: +2 charge. 01.3: gas. 01.4: freezing. 01.5: heat (or evaporate/boil). 01.6: the sequence starting with tiny spheres, then plum pudding, then nuclear model. 01.7: Chadwick. Each part is worth 1 mark, except 01.1 which is 2 marks, totaling 8 marks.

Question 1

AO /

Question Answers Extra information Mark

Spec. Ref.

01.1 (number of protons) 4 1 AO2

5.1.1.4

(number of neutrons) 5 1 5.1.1.5

AO /

Spec. Ref.

01.2 +2 1 AO2

5.1.1.7

5.2.1.2

AO /

Spec. Ref.

01.3 gas 1 AO1

5.2.2.1

AO /

Spec. Ref.

01.4 freezing 1 AO1

5.2.2.1

AO /

Spec. Ref.

01.5 heat allow evaporate / boil 1 AO1

5.2.2.1

AO /

Spec. Ref.

01.6 1 AO1

5.1.1.3

AO /

Spec. Ref.

01.7 chadwick 1 AO1

5.1.1.3

Total Question 1 8

How to answer it

Atomic Structure and States of Matter

What this question tests

This question assesses your ability to identify subatomic particles from a diagram, calculate the charge on an ion, recognize states of matter by particle arrangement, and recall the historical timeline of the atomic model.

Part 01.1

Subatomic Particles

Correct Answers

  • Number of protons: 4
  • Number of neutrons: 5
1 mark for each correct number

Exam Technique

Look closely at the nucleus in Figure 1. Protons are usually shown with a "+" sign. Neutrons are the other particles in the nucleus. Simply count them carefully!

Part 01.2

Calculating Ion Charge

Correct Answer

Tick the box for: +2

Step-by-Step Calculation

  1. Count Protons: There are 4 protons (positive charges).
  2. Count Electrons: There are 2 electrons (negative charges) on the shells.
  3. Sum the charges: (+4) + (-2) = +2.

Key Knowledge

An atom is neutral because it has equal protons and electrons. An ion is charged because it has lost or gained electrons. Beryllium is in Group 2, so it loses 2 electrons to get a full outer shell, forming a +2 ion.

Parts 01.3, 01.4 & 01.5

States of Matter

Correct Answers

  • 01.3: Gas (State C)
  • 01.4: Freezing (B to A)
  • 01.5: Heat it / Evaporate / Boil

Key Knowledge

  • Solid (A): Regular rows, particles touching.
  • Liquid (B): Random arrangement, particles still touching.
  • Gas (C): Random arrangement, particles far apart.

Common Errors

In 01.4, students often confuse Freezing (Liquid to Solid) with Condensing (Gas to Liquid). Always check the starting state (B) and the ending state (A) in the diagram before answering.

Parts 01.6 & 01.7

History of the Atom

Correct Answers

  • 01.6: Tiny spheres → Plum pudding → Nuclear model
  • 01.7: Chadwick

Exam Technique

You must memorize the order of discovery. Think of it as getting more complex over time:

  1. Solid ball (Dalton)
  2. Ball with "raisins" (Thomson - Plum Pudding)
  3. Empty space with a nucleus (Rutherford - Nuclear)

Who did what?

  • Bohr: Discovered that electrons orbit in shells.
  • Chadwick: Discovered the neutron (the last particle to be found because it has no charge).
  • Mendeleev: Created the Periodic Table (not an atomic model!).

Topics

Chemistry · Physics · C1: Atomic Structure and the Periodic Table · C2: Bonding, Structure and the Properties of Matter · P3: Particle Model of Matter

Question and mark scheme from the AQA GCSE Combined Science: Trilogy examination, Chemistry Paper 1 (Foundation), 2023. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.