Why is "Calling it only 'acid rain' and forgetting dry deposition" a common mistake in Acid Deposition?

Why it happens: 'Acid rain' is the familiar everyday phrase. How to avoid it: Use 'acid deposition', which includes wet (rain/snow/hail/fog) AND dry (dust/gases) deposition. Source: 8291 examiner reports — definition questions

Why is "Giving formation steps out of order or with the wrong chemicals" a common mistake in Acid Deposition?

Why it happens: Students remember the gist but jumble the sequence or name the wrong gas. How to avoid it: Learn the ordered pathways: sulfur in fuel → SO2 on combustion → reacts with water + oxygen → sulfuric acid; nitrogen + oxygen in engines → NO → reacts with oxygen + water → nitric acid. Source: 8291 examiner reports — formation of acid deposition

Why is "Mixing up which acid comes from which source" a common mistake in Acid Deposition?

Why it happens: Both acids and sources are learned together. How to avoid it: Sulfur dioxide (power stations) → sulfuric acid; nitrogen monoxide (vehicles) → nitric acid. Match the S to sulfuric and N to nitric.

Why is "Writing acid deposition 'kills fish' with no mechanism" a common mistake in Acid Deposition?

Why it happens: The outcome is obvious, so the mechanism is skipped. How to avoid it: Explain the chain: lowers water pH → damages fish gills → reduces fish populations. The mark is for the mechanism. Source: 8291 examiner reports — impacts questions

Why is "Confusing acid deposition with the greenhouse effect or ozone depletion" a common mistake in Acid Deposition?

Why it happens: All are atmospheric pollution issues studied together. How to avoid it: Keep them separate: acid deposition = acidic pollutants falling and harming ecosystems/buildings; it is not global warming (Topic 8) or ozone loss (7.4).

Why is "Omitting the pH figure in the definition" a common mistake in Acid Deposition?

Why it happens: Students give the idea but not the precise threshold. How to avoid it: State that acidic wet deposition has a pH below 5.6 — this precise figure is creditworthy. Source: 8291 mark scheme — acid deposition definition

Managing the atmosphereCambridge International AS Level Environmental Management 8291

Acid Deposition

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Acid Deposition — Cambridge International AS Level Environmental Management 8291 Study Notes (2025-2027 syllabus)

What acid deposition is (wet and dry, pH below 5.6), how it forms from sulfur dioxide and oxides of nitrogen released by burning fossil fuels and vehicle engines, and its impacts on aquatic life, vegetation and crops, and stone and brick buildings (spec 7.1).

What you’ll learn

Mapped to the Cambridge International A Level 8291 syllabus (2025-2027).

7.1 — Define acid deposition as a mix of air pollutants that deposit from the atmosphere as acidic wet deposition (with a pH below 5.6) or acidic dry deposition.
7.1 — Describe the two types of acid deposition (wet: snow, rain, hail, fog; dry: dust and gases).
7.1 — Outline the formation of acid deposition (sulfuric acid from sulfur dioxide; nitric acid from oxides of nitrogen).
7.1 — Outline the impacts of acid deposition on aquatic environments, vegetation and crops, and stone and brick buildings.

What acid deposition is

Air pollutants deposited as acidic wet (pH below 5.6) or dry deposition.

Acid deposition is a mix of air pollutants that deposit from the atmosphere as acidic wet deposition (with a pH below 5.6) or acidic dry deposition. ("Acid rain" is the most familiar form, but acid deposition is the broader, correct term.)

The pH figure matters: pure rainwater is naturally slightly acidic (about pH 5.6) because carbon dioxide dissolves in it. Rain below pH 5.6 is therefore counted as acidic deposition caused by pollution.

The two types:

Type	What it is	Examples
Wet deposition	Acids dissolved in precipitation, falling to the ground	Acidic rain, snow, hail and fog
Dry deposition	Acidic particles and gases that settle directly, later forming acid when they meet water	Acidic dust and gases

A cross-border problem. Acid-forming gases can travel long distances on the wind before they fall, so a country that burns a lot of fossil fuels can cause acid deposition in neighbouring countries ("transboundary pollution"). This is why managing acid deposition (7.3) often needs international cooperation.

Acid deposition = acidic wet deposition (pH below 5.6) or dry deposition.
Wet: acidic rain, snow, hail, fog. Dry: acidic dust and gases.
Pure rain is ~pH 5.6 (dissolved CO₂); below that is pollution-caused.
'Acid deposition' is the correct broad term, not just 'acid rain'.
Gases travel on the wind, so it is a cross-border (transboundary) problem.

How acid deposition forms

Sulfur dioxide → sulfuric acid; nitrogen monoxide → nitric acid.

Two acids cause most acid deposition, from two main sources. Learn both pathways in order — the formation steps are a common "outline" question.

Pathway 1 — sulfuric acid (from burning fossil fuels):

Fossil fuels (especially coal and oil) contain sulfur compounds.
Combustion of these fossil fuels releases sulfur dioxide gas (SO₂) into the atmosphere.
Sulfur dioxide reacts with water and oxygen in the atmosphere to form sulfuric acid.

Pathway 2 — nitric acid (from vehicle engines):

Nitrogen from the atmosphere reacts with oxygen in the high temperatures of vehicle engines to form nitrogen monoxide gas (NO).
Nitrogen monoxide is released into the atmosphere in vehicle emissions.
Nitrogen monoxide reacts with oxygen and water in the atmosphere to form nitric acid.

Sulfur dioxide and nitrogen monoxide are released, react in the atmosphere to form acids, and fall as acid deposition.

Memory hook: Sulfur dioxide → Sulfuric acid (from power stations); Nitrogen monoxide → Nitric acid (from vehicles).

Fossil fuels contain sulfur → combustion releases SO₂ → reacts with water and oxygen → sulfuric acid.
Engine heat makes nitrogen + oxygen → NO → released in vehicle emissions.
NO reacts with oxygen and water → nitric acid.
Two acids: sulfuric (power stations) and nitric (vehicles).
Both form in the atmosphere before being deposited.

Impacts of acid deposition

Harms fish and aquatic life, damages vegetation and crops, and weathers buildings.

The syllabus limits the impacts to three areas. For each, link the acid to a clear consequence.

Affected area	Impact
Aquatic environments	Acid lowers the pH of lakes and rivers, damaging fish gills (affecting breathing) and reducing fish populations; sensitive species die out and food webs are disrupted. Acid also releases toxic aluminium from soils into water.
Vegetation and crops	Acid causes defoliation (leaves are damaged and fall) and reduced crop yields; it also leaches nutrients (e.g. calcium, magnesium) from soils and can release toxic metals, weakening plants and forests.
Stone and brick buildings	Acid causes enhanced chemical weathering — it reacts with and dissolves stone (especially limestone) and damages brick and mortar, eroding buildings, statues and monuments.

A connected picture. Acid deposition harms whole ecosystems: acidified lakes lose fish, acidified soils weaken forests, and the buildings of affected regions decay faster. Because the gases drift across borders, the country suffering the damage is often not the one that produced the pollution — a key reason management needs international agreement (7.3).

Aquatic: lowers pH, damages fish gills, reduces fish populations, releases toxic aluminium.
Vegetation/crops: defoliation, reduced yields, nutrients leached from soil.
Buildings: enhanced chemical weathering of stone (limestone) and brick.
Whole ecosystems and food webs are disrupted.
Damage often falls in a different country from the source.

How it’s examined

Examined on Paper 1 (structured + possible Section B essay) and Paper 2. Common questions: define acid deposition (state wet/dry and the pH below 5.6); outline the formation of acid deposition (the SO₂→sulfuric and NO→nitric pathways in order — a frequent multi-mark question); and outline its impacts on aquatic environments, vegetation/crops and buildings. Naming the correct chemicals (SO₂, NO) and giving the formation steps in sequence is essential; for impacts, link the acid to a clear mechanism (e.g. lowers pH → damages gills). Management strategies are examined in 7.3.

Sources: Cambridge International AS Level Environmental Management 8291 syllabus (2025-2027); 8291 syllabus 7.1 — acid deposition formation and impacts; 8291 Specimen papers and mark schemes (managing the atmosphere); 8291 Examiner reports — acid deposition formation steps. Last reviewed 2026-05-25.

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Step-by-step worked examples — Acid Deposition

Step-by-step solutions to past-paper-style questions on acid deposition, written exactly the way a tutor would explain them at the board.

1Defining acid deposition precisely
Getting started• AO1, definition
Question
Define acid deposition and state the two types.
Step-by-step solution
1. Step 1
  State the core idea. Acid deposition is a mix of air pollutants deposited from the atmosphere as acid.
2. Step 2
  Add the pH detail for wet deposition. Acidic wet deposition has a pH below 5.6.
3. Step 3
  Name the two types. Wet deposition (acidic rain, snow, hail, fog) and dry deposition (acidic dust and gases).
4. Step 4
  Use the correct term. Say 'acid deposition', not just 'acid rain' — rain is only the wet form.
Answer
Acid deposition is a mix of air pollutants that deposit from the atmosphere as acidic wet deposition (pH below 5.6) or acidic dry deposition. Wet = acidic rain, snow, hail, fog; dry = acidic dust and gases.
Examiner tip
Marks for the definition (with pH below 5.6) and both types. 'Acid rain' alone is incomplete — it misses dry deposition.
2Distinguishing wet and dry deposition
Getting started• AO1, AO2
Question
Sort these into wet or dry deposition: acidic fog, acidic dust, acid rain, acidic gases, acidic snow.
Step-by-step solution
1. Step 1
  Recall the rule. Wet deposition involves precipitation (water falling); dry deposition involves particles and gases settling directly.
2. Step 2
  Wet deposition: acid rain, acidic snow, acidic fog (all forms of precipitation/moisture).
3. Step 3
  Dry deposition: acidic dust and acidic gases (no precipitation).
4. Step 4
  Note the link. Dry-deposited particles and gases can later form acid when they meet water on surfaces.
Answer
Wet deposition: acid rain, acidic snow, acidic fog. Dry deposition: acidic dust, acidic gases.
Examiner tip
A simple sorting task that tests whether candidates know wet = precipitation and dry = particles/gases. Fog counts as wet deposition.
3Outlining the formation of sulfuric acid
Building confidence• AO1, AO2, formation
Question
Outline how sulfuric acid is formed and deposited as acid deposition. [4]
Step-by-step solution
1. Step 1
  Start with the source. Fossil fuels (especially coal and oil) contain sulfur compounds.
2. Step 2
  Combustion step. When these fossil fuels are burned (combustion), sulfur dioxide gas (SO2) is released into the atmosphere.
3. Step 3
  Reaction step. Sulfur dioxide reacts with water and oxygen in the atmosphere to form sulfuric acid.
4. Step 4
  Deposition. The sulfuric acid then falls as acid deposition (e.g. acid rain). Keep the steps in order — that is how the marks are awarded.
Answer
Fossil fuels contain sulfur → combustion releases sulfur dioxide (SO2) → SO2 reacts with water and oxygen in the atmosphere → sulfuric acid forms → falls as acid deposition.
Examiner tip
Each ordered step is a mark: sulfur in fuel, SO2 released on combustion, reacts with water + oxygen, forms sulfuric acid. Naming SO2 is important.
4Outlining the formation of nitric acid
Building confidence• AO1, AO2, formation
Question
Outline how nitric acid is formed from vehicle emissions. [4]
Step-by-step solution
1. Step 1
  Source of the nitrogen. Nitrogen from the atmosphere reacts with oxygen in the high temperatures of vehicle engines.
2. Step 2
  Gas formed. This forms nitrogen monoxide gas (NO).
3. Step 3
  Release. Nitrogen monoxide is released into the atmosphere in vehicle emissions.
4. Step 4
  Reaction. Nitrogen monoxide reacts with oxygen and water in the atmosphere to form nitric acid, which falls as acid deposition.
Answer
In the high temperatures of vehicle engines, nitrogen + oxygen → nitrogen monoxide (NO) → released in vehicle emissions → NO reacts with oxygen and water in the atmosphere → nitric acid → acid deposition.
Examiner tip
Ordered steps each earn a mark: high engine temperature combines nitrogen + oxygen, forms NO, released in emissions, reacts with oxygen + water to form nitric acid. The 'high temperature of engines' detail is often missed.
5Explaining impacts on aquatic environments
Stretch• AO2, explain, impacts
Question
Explain how acid deposition affects aquatic environments. [4]
Step-by-step solution
1. Step 1
  State the chemical effect. Acid deposition lowers the pH of lakes and rivers, making the water more acidic.
2. Step 2
  Direct effect on fish. The acidic water damages fish gills, affecting their ability to take in oxygen, so fish populations fall.
3. Step 3
  Indirect effect. Acid also releases toxic aluminium from soils and sediments into the water, which is harmful to aquatic life.
4. Step 4
  Wider consequence. Sensitive species die out, reducing biodiversity and disrupting aquatic food webs.
Answer
Acid deposition lowers the pH of lakes and rivers; the acidic water damages fish gills and reduces fish populations, and releases toxic aluminium into the water. Sensitive species die out, reducing biodiversity and disrupting food webs.
Examiner tip
'Explain' needs the mechanism (lower pH → gill damage → fewer fish), not just 'kills fish'. The aluminium-release and biodiversity points add depth.
6Planning an essay on managing a transboundary pollutant
Stretch• AO2, AO3, essay technique, evaluation
Question
Plan a top-band answer to: 'Acid deposition can only be reduced through international cooperation.' To what extent do you agree? [20]
Step-by-step solution
1. Step 1
  Decode the command. 'To what extent' = reach a supported judgement; set a criterion (here, the scale of the pollution).
2. Step 2
  Case FOR cooperation. Acid-forming gases drift across borders, so the country causing the pollution is often not the one harmed — only international agreement can make polluters reduce emissions.
3. Step 3
  Case AGAINST (national action helps too). A country can cut its own emissions with national measures — flue gas desulfurisation, catalytic converters, switching from fossil fuels — reducing the acid it produces and exports (links to 7.3).
4. Step 4
  Set the criterion. Judge by the scale: where pollution stays within a country, national action suffices; where it crosses borders, cooperation is essential.
5. Step 5
  Conclude. International cooperation is essential for the cross-border part of the problem, but national action is also effective and necessary — so 'only through international cooperation' is an overstatement; both are needed.
Answer
Decode 'to what extent'; argue FOR cooperation (gases cross borders, polluter is not always the victim) and AGAINST (national measures like desulfurisation and catalytic converters cut a country's own emissions); set the criterion of pollution scale; conclude cooperation is essential for transboundary effects but national action is also effective — so the statement is an overstatement.
Examiner tip
Section B rewards a balanced argument plus an explicit, criterion-based judgement. The transboundary point (polluter is not always the victim) is the key AO3 idea here.

Model Answers — Acid Deposition

High-scoring sample answers for acid deposition on the Cambridge International AS Level 8291 paper, with examiner-style notes mapping each response to the mark scheme and assessment objectives.

Question 1
2 marks
[EASY] Define the term acid deposition. [2]
Model answer
Acid deposition is a mix of air pollutants that deposit from the atmosphere as acidic wet deposition (with a pH below 5.6) or acidic dry deposition.
Why this scores
1 mark for the deposition-of-air-pollutants idea, 1 mark for distinguishing wet (pH below 5.6) and dry. Quoting the pH is the surest way to the second mark.
Question 2
3 marks
[EASY] State one impact of acid deposition on each of: aquatic environments, vegetation, and buildings. [3]
Model answer
Aquatic environments: damages fish gills / reduces fish populations.

Vegetation: defoliation (leaf loss) / reduced crop yields.

Buildings: enhanced chemical weathering of stone and brick.
Why this scores
One mark per area with a correct impact. Be specific — 'harms nature' is too vague for the mark.
Question 3
8291 Paper 1 style (formation, AO1/AO2)4 marks
[MEDIUM] Outline how sulfur dioxide from power stations leads to acid deposition. [4]
Model answer
Fossil fuels such as coal and oil contain sulfur compounds. When they are burned (combustion) in power stations, sulfur dioxide gas (SO2) is released into the atmosphere. The sulfur dioxide then reacts with water and oxygen in the atmosphere to form sulfuric acid, which falls to the ground as acid deposition (e.g. acid rain).
Why this scores
Four ordered marking points: sulfur in fossil fuels; SO2 released on combustion; reacts with water and oxygen; forms sulfuric acid. Naming SO2 and keeping the order are essential.
Question 4
5 marks
[MEDIUM] Explain the impacts of acid deposition on aquatic environments and on buildings. [5]
Model answer
Aquatic environments: acid deposition lowers the pH of lakes and rivers, making them more acidic. This damages fish gills, reducing their ability to absorb oxygen, so fish populations fall; acid also releases toxic aluminium from soils into the water. Sensitive species die out, reducing biodiversity and disrupting food webs.

Buildings: acid reacts with stone (especially limestone) and brick, causing enhanced chemical weathering. This dissolves and erodes the surface of buildings, statues and monuments, so they decay and are damaged faster than normal.
Why this scores
Marks for the aquatic mechanism (lower pH → gill damage → fewer fish, plus aluminium/biodiversity) and the building mechanism (acid reacts with stone → enhanced chemical weathering). The command 'explain' needs the cause-and-effect link, not just the outcome.
Question 5
8291 Paper 1 style (extended, AO1/AO2)8 marks
[HARD] Outline how both sulfuric acid and nitric acid are formed, and explain the impacts of the resulting acid deposition on the environment. [8]
Model answer
Formation of sulfuric acid. Fossil fuels contain sulfur compounds; when burned (combustion), they release sulfur dioxide gas (SO2). The SO2 reacts with water and oxygen in the atmosphere to form sulfuric acid.

Formation of nitric acid. In the high temperatures of vehicle engines, nitrogen and oxygen from the air react to form nitrogen monoxide gas (NO), which is released in vehicle emissions. The NO reacts with oxygen and water in the atmosphere to form nitric acid.

Both acids fall as wet deposition (rain, snow, hail, fog) or settle as dry deposition (dust, gases).

Impacts.

Aquatic environments: acid lowers the pH of lakes and rivers, damaging fish gills and reducing fish populations, and releasing toxic aluminium — disrupting food webs.

Vegetation and crops: acid causes defoliation and reduced crop yields, and leaches nutrients from the soil, weakening plants and forests.

Buildings: acid causes enhanced chemical weathering, dissolving stone (limestone) and damaging brickwork, so buildings and monuments erode faster.
Why this scores
Top band: both formation pathways with the correct chemicals (SO2 → sulfuric, NO → nitric) in order, AND the three impact areas each with a mechanism. A balanced answer that covers formation and impacts (not just one) secures the full range of marks.
Question 6
8291 Paper 1 Section B style (essay, AO2/AO3)20 marks
[HARD] 'Acid deposition can only be reduced through international cooperation.' To what extent do you agree? [20]
Model answer
Introduction. Acid deposition forms when sulfur dioxide and oxides of nitrogen, released by burning fossil fuels and by vehicles, react in the atmosphere and fall as acid. Because these gases travel on the wind, the pollution often crosses borders. This essay weighs the need for international cooperation against what individual countries can achieve alone, judging by the scale at which the pollution acts.

The case that international cooperation is essential.

Acid-forming gases drift long distances, so the country that produces the pollution is often not the one that suffers the acid deposition (a transboundary problem).

A country that is harmed cannot fix the problem alone if the pollution comes from a neighbour, so only international agreement can require the polluting countries to cut their emissions.

Shared resources (rivers, forests, fisheries) that cross borders also need coordinated protection.

The case that national action is also effective.

A country can cut its own emissions with national measures: flue gas desulfurisation and fuel desulfurisation remove sulfur dioxide from power stations; catalytic converters reduce oxides of nitrogen from vehicles; switching from fossil fuels to cleaner energy reduces both.

National legislation (and the polluter pays principle) can force industry and motorists to reduce emissions now, without waiting for global agreement.

These measures reduce the acid a country both suffers and exports, so they help even before cooperation is reached.

Judgement. The decisive factor is the scale of the pollution. Where acid-forming gases stay within a country, national action alone can solve the problem; where they cross borders, international cooperation is essential because no single country controls the source. In reality acid deposition is both national and transboundary, so the statement is an overstatement: international cooperation is essential for the cross-border part, but national measures are effective and necessary too. The most successful approach combines strong national emission controls with international agreements so that all the countries contributing to the problem reduce their emissions together.
Why this scores
Top band: sets the criterion (scale of the pollution) in the introduction; develops both sides with accurate content (transboundary drift vs national measures like desulfurisation and catalytic converters); and reaches an explicit, supported judgement (an overstatement — both national and international action are needed). The transboundary argument is the route to the top AO3 band.

Key Definitions and Keywords — Acid Deposition

Definitions to memorise and the exact keywords mark schemes credit for acid deposition answers — sharpened from recent examiner reports for the 2026 Cambridge International AS Level 8291 sitting.

Acid deposition
Examiner keyword
A mix of air pollutants that deposit from the atmosphere as acidic wet deposition (pH below 5.6) or acidic dry deposition.
Wet deposition
Examiner keyword
Acid deposited dissolved in precipitation — acidic rain, snow, hail or fog.
Related: def dry deposition
Dry deposition
Examiner keyword
Acidic particles and gases (dust and gases) that settle directly from the atmosphere.
Related: def wet deposition
Sulfur dioxide (SO2)
Examiner keyword
A gas released when fossil fuels containing sulfur are burned; reacts with water and oxygen to form sulfuric acid.
Nitrogen monoxide (NO)
Examiner keyword
A gas formed when nitrogen and oxygen react in the high temperatures of vehicle engines; reacts with oxygen and water to form nitric acid.
Sulfuric acid
Examiner keyword
An acid formed when sulfur dioxide reacts with water and oxygen in the atmosphere; a major component of acid deposition.
Nitric acid
Examiner keyword
An acid formed when nitrogen monoxide reacts with oxygen and water in the atmosphere; a major component of acid deposition.
Defoliation
Examiner keyword
The loss or damage of leaves from plants and trees, here caused by acid deposition.
Enhanced chemical weathering
Examiner keyword
The accelerated breakdown of stone and brick when acid reacts with and dissolves the material, damaging buildings and monuments.
Transboundary pollution
Examiner keyword
Pollution that crosses national borders, so the country producing it is often not the one that suffers its effects.
Combustion
The burning of a fuel; combustion of fossil fuels releases pollutant gases such as sulfur dioxide.

Common Mistakes and Misconceptions — Acid Deposition

The traps other students keep falling into on acid deposition questions — taken from recent Cambridge International AS Level 8291 examiner reports and mark schemes — and how to avoid them.

✕Calling it only 'acid rain' and forgetting dry deposition
8291 examiner reports — definition questions
Why it happens
'Acid rain' is the familiar everyday phrase.
How to avoid it
Use 'acid deposition', which includes wet (rain/snow/hail/fog) AND dry (dust/gases) deposition.
✕Giving formation steps out of order or with the wrong chemicals
8291 examiner reports — formation of acid deposition
Why it happens
Students remember the gist but jumble the sequence or name the wrong gas.
How to avoid it
Learn the ordered pathways: sulfur in fuel → SO2 on combustion → reacts with water + oxygen → sulfuric acid; nitrogen + oxygen in engines → NO → reacts with oxygen + water → nitric acid.
✕Mixing up which acid comes from which source
Why it happens
Both acids and sources are learned together.
How to avoid it
Sulfur dioxide (power stations) → sulfuric acid; nitrogen monoxide (vehicles) → nitric acid. Match the S to sulfuric and N to nitric.
✕Writing acid deposition 'kills fish' with no mechanism
8291 examiner reports — impacts questions
Why it happens
The outcome is obvious, so the mechanism is skipped.
How to avoid it
Explain the chain: lowers water pH → damages fish gills → reduces fish populations. The mark is for the mechanism.
✕Confusing acid deposition with the greenhouse effect or ozone depletion
Why it happens
All are atmospheric pollution issues studied together.
How to avoid it
Keep them separate: acid deposition = acidic pollutants falling and harming ecosystems/buildings; it is not global warming (Topic 8) or ozone loss (7.4).
✕Omitting the pH figure in the definition
8291 mark scheme — acid deposition definition
Why it happens
Students give the idea but not the precise threshold.
How to avoid it
State that acidic wet deposition has a pH below 5.6 — this precise figure is creditworthy.

Practice questions

Exam-style questions with step-by-step worked solutions. Try one before checking the method.

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Acid Deposition

Short Study Notes in the form of Slides

Short Study Notes — Acid Deposition

Detailed Notes

What you’ll learn

How it’s examined

1Defining acid deposition precisely

2Distinguishing wet and dry deposition

3Outlining the formation of sulfuric acid

4Outlining the formation of nitric acid

5Explaining impacts on aquatic environments

6Planning an essay on managing a transboundary pollutant

Acid deposition

Wet deposition

Dry deposition

Sulfur dioxide (SO2)

Nitrogen monoxide (NO)

Sulfuric acid

Nitric acid

Defoliation

Enhanced chemical weathering

Transboundary pollution

Combustion

✕Calling it only 'acid rain' and forgetting dry deposition

✕Giving formation steps out of order or with the wrong chemicals

✕Mixing up which acid comes from which source

✕Writing acid deposition 'kills fish' with no mechanism

✕Confusing acid deposition with the greenhouse effect or ozone depletion

✕Omitting the pH figure in the definition

Practice questions

Past paper style quiz