C1.4a Atmosphere card sort Cut up the following cards and then sort them to show the names, formulae and abundances of the gases in air.
carbon dioxide
oxygen
nitrogen
argon
N2
CO2
Ar
O2
78%
21%
0.04%
0.9%
Cut up the following cards and then sort them to show the names, formulae and abundances of the gases in air.
carbon dioxide
oxygen
nitrogen
argon
N2
CO2
Ar
O2
78%
21%
0.04%
0.9%
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack. This document may have been altered from the original.
C1.4b Human effects on the atmosphere What do they do?
1 Very large amounts of rice are grown around the world. It provides more than 20% of energy from food for the world population. The growth of rice in rice fields produces methane. The amount of methane in the air is increasing as more rice is grown to feed the increasing world population.
2 Cows, sheep and goats produce methane from their digestive systems. The number of cattle is increasing to feed the growing world population. This is increasing the amount of methane in the air.
3 All fossil fuels contain carbon and so produce carbon dioxide when they are burned. Increasing amounts of fossil fuels are being burned and this is increasing the amount of carbon dioxide in the atmosphere.
4 A large proportion of the Earth’s surface is covered by rainforests. These trees absorb a lot of carbon dioxide. Over recent years, there has been much deforestation where the trees are cut down and burned to create land for farming. The loss of these trees means much less carbon dioxide can be absorbed by trees and is leading to increasing levels of carbon dioxide in the air.
5 When fossil fuels are burned in a furnace at a power station or in an engine, the temperature is so high that the nitrogen and oxygen in the air react together to form nitrogen oxides (NO and NO2). This is increasing the amount of nitrogen oxides in the atmosphere.
6 Many fossil fuels contain small amounts of sulfur. When these fuels are burned, this sulfur is converted into sulfur dioxide and the amount of sulfur dioxide in the air is increasing.
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack. This document may have been altered from the original.
C1.4c The gases in air Name
Class
Date
The atmosphere is a mixture of gases that surround the Earth. Air is the mixture of gases in the lower part of the atmosphere. About 99% of the air is made up of nitrogen and oxygen. There are small amounts of other gases, which make up the remaining 1%. Some of these are noble gases, particularly argon. A small amount of carbon dioxide is also found in air. Water vapour is also present in the air. The amount of water vapour changes from day to day, and so it is not included when showing the composition of dry air. The pie chart shows the proportions of gases in dry air. 1 Label the part of the pie chart that represents nitrogen. 2
Label the part of the pie chart that represents oxygen.
3
Label the part of the pie chart that represents other gases.
4
What percentage of the air is nitrogen? _________________________
5
What percentage of the air is oxygen? _________________________
6
The table below shows the formulae of some of the other gases in air. Complete the table to show their names. Formula
Name
CO2 H2O Ar 7
a
Which of the gases in the table is not included in the pie chart?
b
Explain why it is not included.
_______________________________________________________________ 8
Pollution from human activities can cause small changes to the gases in the atmosphere. a
Name two gases in the air that would change as a result of pollution. _______________________________________________________________
b
Would the percentage amount of these gases increase or decrease? _______________________________________________________________
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack. This document may have been altered from the original.
C1.4d Using ice core data There is little evidence about the Earth’s atmosphere when it was young. However, there is evidence of more recent changes in the atmosphere. Some of this comes from analysis of ice cores drilled in Greenland and the Antarctic. The ice analysed in these cores has built up over thousands of years as more and more snow fell and was compacted. The deeper the ice, the older it is. Scientists drill down and pull out a long column of ice. The longest is over 3.6 km long. The oldest ice analysed is over 400 000 years old, although the Earth is thought to be 4 500 000 000 years old. There are bubbles of air trapped in the ice from when the snow fell. Scientists have analysed many of these air bubbles to measure the amount of each gas, showing what was in the air at the time the snow fell. The most important information has been about the amount of carbon dioxide in the air. The graph shows data from the ice cores showing how the amount of carbon dioxide in the air has changed over the last 400 000 years.
Ice core data showing amount of carbon dioxide in air up to 1950.
1
What is trapped in the ice from which measurements about the atmosphere in the past are made?
2
Describe in as much detail as you can what has happened to the amount of carbon dioxide in the air over the 400 000 years before 1950.
3
How could data from other research groups and other places validate this idea?
4
Explain why ice core data could not be used to find how much carbon dioxide was in the air when the Earth was young.
5
The concentration of carbon dioxide in the atmosphere today is about 0.038%. Comment on this level compared to levels over the last 400 000 years.
6
Suggest different reasons why carbon dioxide levels have increased in recent years.
7
Does this ice core data confirm that humans are causing increasing levels of carbon dioxide? Explain your answer.
Extra challenge 8
Suggest why ice core data is not used to monitor recent changes in levels of carbon dioxide.
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack. This document may have been altered from the original.
C1.4e Burning fossil fuels Name
Class
Date
In this experiment you are going to deduce which gas is used when fossil fuels are burned and what gases are produced. You will do the first experiment and your teacher will demonstrate the second. In the second experiment, cobalt chloride paper turns from blue to pink when in the presence of water, and limewater turns cloudy in the presence of carbon dioxide.
Apparatus
Health and safety
Class practical
●
Wear eye protection
●
Be careful of hot glass
●
Limewater is an irritant
●
Cobalt chloride is toxic. Wash your hands after the experiment.
tea light candle on a piece of cork marker pen washing up bowl
beaker or jam jar
Method A Half fill a washing up bowl with water. B Place the tea light (on the cork) on the surface of the water and light the tea light. C Mark a line with a permanent marked about 3 cm from the open end of a beaker or jam jar. D Place the beaker or jam jar over the candle so that when you first place it in the water the water is at the level of the line. E Hold the beaker / jam jar in place until the tea light goes out and then mark the new water level inside the beaker / jam jar.
Recording your results 1
Record the results you got for each experiment in suitable tables.
Considering your results/conclusions 2
a
In the class experiment, calculate the percentage of air that was used up when the candle burned.
b Explain what this tells you. 3
For the demonstration, explain what the results tell you about the gases formed when a hydrocarbon fuel, such as wax, burns.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack. This document may have been altered from the original.