1
2026 OCR GCSE Prediction Exam
Combined Science B (Twenty First
Century Science)
J260/04 Combined
Science(Foundation
Tier)
Complete Question paper with
Marking Scheme Combined
GCSE (9–1) Combined Science B (Twenty
First Century Science)
J260/04 Combined Science (Foundation Tier)
Time allowed: 1 hour 45 minutes
You must have: F
• a ruler (cm/mm)
• the Data and Equation Sheet for GCSE (9–1) Combined Science B (inside this document)
You can use:
• an HB pencil
• a scientific or graphical calcul
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use thelined
pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might begiven for
using a correct method, even if your answer is wrong.
Turn-over
, 2
INFORMATION
• The total mark for this paper is 75.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 28 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/8690/2] OCR is an exempt Charity
DC (SL/CB) 354468/6a Turn over
1 This question is about acids and metals.
(a) This is the symbol equation for the reaction between magnesium, and hydrochloric acid:
(i) Which gas is made when magnesium reacts with hydrochloric acid?
Tick (✓) one box.
Carbon dioxide
Hydrogen
Oxygen
Steam
[1]
(ii) Which salt is made when magnesium reacts with hydrochloric acid?
Tick (✓) one box.
Magnesium carbonate
Magnesium chloride
Magnesium hydroxide
Magnesium oxide
[1]
Turn-over
, 3
(iii) Complete the sentences to describe how magnesium bonds with chlorine.
Use words from the list.
gaining ions losing molecules polymers sharing
Each Mg atom becomes Mg2+ by ................................. two electrons.
Each Cl atom becomes Cl – by ................................. one electron.
The new particles formed, Mg2+ and Cl –, are called ................................ .
[3]
(b)
(i) Hydrochloric acid is made by dissolving hydrogen chloride in water.
What forms when acids dissolve in water?
Tick (✓) one box.
Cl –
Cl +
–
H
H+
[1]
( ii) The list shows the order of reactivity of some elements from most reactive to least reactive.
Turn-over
, 4
Most – Rubidium
Potassium
Magnesium
Aluminium
Carbon
Zinc
Iron
Least – Copper
Why is magnesium extracted by electrolysis and not by reaction with carbon?
..........................................................................................................................................................
.................................................................................................................................................. [1]
(c) A student investigates the reaction between magnesium and different concentrations ofhydrochloric
acid.
The student times how long it takes to collect 50 cm3 of gas.The results are shown in the table:
Concentration of hydrochloric acid Time taken
Turn-over
2026 OCR GCSE Prediction Exam
Combined Science B (Twenty First
Century Science)
J260/04 Combined
Science(Foundation
Tier)
Complete Question paper with
Marking Scheme Combined
GCSE (9–1) Combined Science B (Twenty
First Century Science)
J260/04 Combined Science (Foundation Tier)
Time allowed: 1 hour 45 minutes
You must have: F
• a ruler (cm/mm)
• the Data and Equation Sheet for GCSE (9–1) Combined Science B (inside this document)
You can use:
• an HB pencil
• a scientific or graphical calcul
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use thelined
pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might begiven for
using a correct method, even if your answer is wrong.
Turn-over
, 2
INFORMATION
• The total mark for this paper is 75.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 28 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/8690/2] OCR is an exempt Charity
DC (SL/CB) 354468/6a Turn over
1 This question is about acids and metals.
(a) This is the symbol equation for the reaction between magnesium, and hydrochloric acid:
(i) Which gas is made when magnesium reacts with hydrochloric acid?
Tick (✓) one box.
Carbon dioxide
Hydrogen
Oxygen
Steam
[1]
(ii) Which salt is made when magnesium reacts with hydrochloric acid?
Tick (✓) one box.
Magnesium carbonate
Magnesium chloride
Magnesium hydroxide
Magnesium oxide
[1]
Turn-over
, 3
(iii) Complete the sentences to describe how magnesium bonds with chlorine.
Use words from the list.
gaining ions losing molecules polymers sharing
Each Mg atom becomes Mg2+ by ................................. two electrons.
Each Cl atom becomes Cl – by ................................. one electron.
The new particles formed, Mg2+ and Cl –, are called ................................ .
[3]
(b)
(i) Hydrochloric acid is made by dissolving hydrogen chloride in water.
What forms when acids dissolve in water?
Tick (✓) one box.
Cl –
Cl +
–
H
H+
[1]
( ii) The list shows the order of reactivity of some elements from most reactive to least reactive.
Turn-over
, 4
Most – Rubidium
Potassium
Magnesium
Aluminium
Carbon
Zinc
Iron
Least – Copper
Why is magnesium extracted by electrolysis and not by reaction with carbon?
..........................................................................................................................................................
.................................................................................................................................................. [1]
(c) A student investigates the reaction between magnesium and different concentrations ofhydrochloric
acid.
The student times how long it takes to collect 50 cm3 of gas.The results are shown in the table:
Concentration of hydrochloric acid Time taken
Turn-over
