Metals are extracted from ores in the Earth’s crust.

Some ores contain metal carbonates.

Name the type of reaction that occurs when a metal carbonate is heated.

A chemical reaction happens when calcium carbonate is heated.

Write down the symbol equation for this reaction.

Include state symbols.

A student used the apparatus below to investigate what happens when metal carbonates are heated.

The student:

• started the clock when he started heating the carbonate
• stopped the clock when carbon dioxide was produced

The student's results are shown in the table below.

What type of graph should the student draw from these results?

Explain why.

How did the student know when to stop the clock?

Use the diagram to help you answer the question.

Complete the following sentences.

The more reactive the metal in the carbonate is, the time it takes for the production of carbon dioxide to start.

Therefore, the most reactive of the carbonates tested is carbonate.

A student investigated the thermal decomposition of copper carbonate.

The student used the apparatus below to measure how long it took for carbon dioxide to be produced.

The student also noted what happened during each minute for three minutes.

Write the symbol equation for the thermal decomposition of copper carbonate.

Include state symbols.

The student wrote down her observations in the table below.

Suggest the reason for the student’s observations between 0 and 60 seconds.

Explain the student’s observations between 61 and 120 seconds.

Explain the student’s observations between 121 and 180 minutes.

Metal carbonates undergo a thermal decomposition reaction when heated.

Which solid product is formed when magnesium carbonate is heated?

A student used the apparatus shown below to investigate the thermal decomposition of four metal carbonates.

The student heated each metal carbonate for 5 minutes.

The table shows the student's results.

Why do the contents of the test tube lose mass during the investigation?

Explain the results obtained for potassium carbonate.

State how you can use the reactivity series to predict which metal carbonate reacts most easily when heated.

The graph below shows how the percentage of carbon dioxide in the atmosphere changed in the last 4500 million years.

Describe how the percentage of carbon dioxide has changed in the last 4500 million years.

Give two reasons why the percentage of carbon dioxide has changed.

The graph below shows how the percentage of carbon dioxide in the atmosphere changed in the last 250 years.

Is the change in the percentage of carbon dioxide a reason for concern?

Answer yes or no, and explain the reason for your answer.

Petrol contains carbon and some sulfur.

When petrol is burned, the products of combustion may be released into the atmosphere.

These products include carbon dioxide and sulfur dioxide.

Explain why some scientists are concerned about the environmental impacts of releasing carbon dioxide and sulfur dioxide into the atmosphere.

You should refer to both carbon dioxide and sulfur dioxide in your answer.