Monday 18 May 2026 ? Morning
GCSE (9?1) Combined Science A
(Gateway Science)
J250/09 Chemistry (Higher Tier)
Time allowed: 1 hour 10 minutes
*
2
6 You must have:
9 ? a ruler (cm/mm) H5 ? the Data Sheet for GCSE (9?1) Combined Science A
1 (Chemistry) (inside this document)
6
4 You can use:
9 ? a scientific or graphical calculator
6 ? an HB pencil
0 * J 2 5 0 0 9 *
*
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
the lined 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 be
given for using a correct method, even if your answer is wrong.
INFORMATION
? The total mark for this paper is 60.
? 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 24 pages.
ADVICE
? Read each question carefully before you start your answer.
© Cambridge OCR 2026 [601/8687/2] Cambridge OCR is an exempt Charity
DC (SL/SG) 363694/6 Turn over
for more:
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1 An isotope has an atomic number and a mass number.
Which equation is used to work out the number of neutrons?
A Number of neutrons = atomic number
B Number of neutrons = atomic number + mass number
C Number of neutrons = mass number
D Number of neutrons = mass number ? atomic number
Your answer [1]
2 A mixture contains two liquids.
One liquid has a boiling point of 78 °C.
Another liquid has a boiling point of 85 °C.
Which technique would be suitable for separating the two liquids?
A Crystallisation
B Filtration
C Fractional distillation
D Thin layer chromatography
Your answer [1]
3 Thomson developed the plum pudding model of the atom.
Which statement correctly describes this model?
A Atoms are small, indivisible spheres.
B Atoms contain very small, negatively charged electrons.
C Atoms have a small, positively charged nucleus.
D Atoms have both protons and neutrons in the nucleus.
Your answer [1]
© Cambridge OCR 2026
for more:
, 3
4 The diagram shows a chromatogram.
It is produced by paper chromatography of a dye.
Solvent front
Q R
Dye spot
P S
Baseline
What is the correct equation for calculating the Rf value of the dye?
P
A Rf = Q
P
B Rf = R
S
C Rf = Q
S
D Rf = R
Your answer [1]
© Cambridge OCR 2026 Turn over
for more:
GCSE (9?1) Combined Science A
(Gateway Science)
J250/09 Chemistry (Higher Tier)
Time allowed: 1 hour 10 minutes
*
2
6 You must have:
9 ? a ruler (cm/mm) H5 ? the Data Sheet for GCSE (9?1) Combined Science A
1 (Chemistry) (inside this document)
6
4 You can use:
9 ? a scientific or graphical calculator
6 ? an HB pencil
0 * J 2 5 0 0 9 *
*
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
the lined 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 be
given for using a correct method, even if your answer is wrong.
INFORMATION
? The total mark for this paper is 60.
? 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 24 pages.
ADVICE
? Read each question carefully before you start your answer.
© Cambridge OCR 2026 [601/8687/2] Cambridge OCR is an exempt Charity
DC (SL/SG) 363694/6 Turn over
for more:
, 2
Section A
You should spend a maximum of 20 minutes on this section.
Write your answer to each question in the box provided.
1 An isotope has an atomic number and a mass number.
Which equation is used to work out the number of neutrons?
A Number of neutrons = atomic number
B Number of neutrons = atomic number + mass number
C Number of neutrons = mass number
D Number of neutrons = mass number ? atomic number
Your answer [1]
2 A mixture contains two liquids.
One liquid has a boiling point of 78 °C.
Another liquid has a boiling point of 85 °C.
Which technique would be suitable for separating the two liquids?
A Crystallisation
B Filtration
C Fractional distillation
D Thin layer chromatography
Your answer [1]
3 Thomson developed the plum pudding model of the atom.
Which statement correctly describes this model?
A Atoms are small, indivisible spheres.
B Atoms contain very small, negatively charged electrons.
C Atoms have a small, positively charged nucleus.
D Atoms have both protons and neutrons in the nucleus.
Your answer [1]
© Cambridge OCR 2026
for more:
, 3
4 The diagram shows a chromatogram.
It is produced by paper chromatography of a dye.
Solvent front
Q R
Dye spot
P S
Baseline
What is the correct equation for calculating the Rf value of the dye?
P
A Rf = Q
P
B Rf = R
S
C Rf = Q
S
D Rf = R
Your answer [1]
© Cambridge OCR 2026 Turn over
for more:
