JAMB - Chemistry (1985 - No. 3)
If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be?
automobile exhaust and biological decomposition
combustion of coal and automobile exhaust
biological decomposition only
combustion of coal, automobile exhaust and biological decomposition
combustion of coal and biological decomposition