GCSE CHEMISTRY B FIRST CENTURY SCIENCE) — Actual May 2025 PAST PAPER: Breadth in Chemistry (Foundation Tier). All Assessment Questions & Mark Scheme [OCR J258/Oll Exam Resource Summary The GCSE (9-1) Chemistry B (Twenty First Century Science) May 2025 Fou

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1 Greenhouse gases absorb energy emitted by the Earth.

(a) Carbon dioxide is a greenhouse gas.

(i) Which of these gases is another greenhouse gas?

Tick (✓) one box.

Methane

Nitrogen

Oxygen
[1]

(ii) Which two statements describe the possible effects of increased levels of greenhouse gases?

Tick (✓) two boxes.

Decreased algae growth in water.

Flooding of low land.

Increased oxygen in the atmosphere.

Melting of polar ice caps.
[2]

(iii) Suggest two ways the amount of carbon dioxide in the environment can be reduced.

1 .......................................................................................................................................................

..........................................................................................................................................................

2 .......................................................................................................................................................

..........................................................................................................................................................
[2]




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(b) The concentration of carbon dioxide in the atmosphere has increased over time.

Fig. 1.1 shows the concentration of carbon dioxide in the atmosphere over a 50-year period.

Fig. 1.1

440
420

400
380
Concentration
360
(ppm)
340
320

300
280
1960 1970 1980 1990 2000 2010
Year

Fig. 1.2 shows the number of cars being used in the USA over the same 50-year period.

Fig. 1.2

300


250

200

Number of 150
cars
(millions)
100


50

0
1960 1970 1980 1990 2000 2010
Year




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