Beatty 18.1_Air_WS2 - Carbon Cycle and Ozone_Answers

1 Beatty Secondary School Science Department (Chemistry Unit) Chemistry 6092 Name: ___________________________________ ( ) Date: _______________ Class: 4E1 TOPIC: AIR – ATMOSPHERE & ENVIRONMENT (WORKSHEET 2) Learning Objectives: (a) Discuss the importance of the ozone layer and the problems involved with the depletion of ozone by reaction with chlorine -containing compounds, chlorofluorocarbons (CFCs). (b) Describe the carbon cycle in simple terms, to include (i) the processes of combustion, respiration and photosynthesis, (ii) how the carbon cycle regulates the amount of carbon dioxide in the atmosphere. (c) State that carbon dioxide and methane are greenhouse gases and may contribute to global warming, give the sources of these gases and discuss the possible consequences of an increase in global warming. Multiple-Choice Questions 1 Which statement about the ozone layer is true? A It is a pollutant in the stratosphere. B It absorbs some of the ultraviolet radiation from the Sun. C Excess greenhouse gases can cause its depletion. D It is destroyed when fluorine atoms react with the ozone molecules. ( B ) 2 In the past, CFC compounds were used as aerosol propellants. The structure of one CFC compound is shown. Which element in this compound can cause the depletion of ozone? A carbon B chlorine C fluorine D hydrogen ( B ) 3 Which substance is the main cause of the greenhouse effect? A carbon dioxide B chlorofluorocarbons (CFCs) C ozone D sulfur dioxide ( A ) 4 The global atmospheric concentration of carbo n dioxide has increased in the last 200 years. What could be causing this increase? 1 emissions from motor vehicles 2 photosynthesis 3 power stations using coal and oil A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 ( B )

2 5 The diagram shows part of the carbon cycle. What are processes P, Q and R? P Q R A combustion photosynthesis respiration B photosynthesis combustion respiration C respiration combustion photosynthesis D respiration photosynthesis combustion ( D ) 6 Which row shows both the correct source and the correct effect of the named pollutant? pollutant source effect A carbon monoxide incomplete combustion of carbon-containing materials global warming B oxides of nitrogen decaying vegetable matter global warming C ozone photochemical reactions acid rain D sulfur dioxide volcanoes acid rain ( D ) 7 In wh at w ay do chlorof lurocarbons, methane and nitrogen dioxide a ffect the atmosphere and the environment? chloroflurocarbons methane nitrogen dioxide A acid rain depletion of the ozone layer greenhouse gas B depletion of the ozone layer acid rain global warming C depletion of the ozone layer greenhouse gas acid rain D global warming depletion of the ozone layer a