Oquizy

Xinyi wondered why plants are called “carbon sinks.” Which process in the carbon cycle reduces the greenhouse effect?

Combustion of fossil fuels Photosynthesis by plants Respiration by animals Volcanic eruptions

Xinyi is learning about atmospheric gases. She found out that nitrogen makes up 78% of dry air and oxygen about 21%. Which feature of nitrogen explains why it does not easily react in the atmosphere?

It exists as single atoms It has a low boiling point It has a strong triple covalent bond It is denser than oxygen

Methane is 25 times more potent than carbon dioxide as a greenhouse gas. Which source is a major contributor to atmospheric methane levels?

Burning fossil fuels Decomposition in landfills and rice paddies Evaporation from oceans Photosynthesis in forests

Xinyi saw a poster showing carbon monoxide and asked John, “Where does it come from?” Which is a common source of carbon monoxide in urban areas?

Breathing of humans Decomposition of plants Incomplete combustion of petrol in cars Lightning

John was puzzled by how CFCs damage the ozone layer. Which correctly explains how CFCs destroy ozone?

CFCs break down ozone directly CFCs prevent UV light from reaching ozone CFCs produce oxygen from water vapour Chlorine radicals from CFCs break down ozone molecules

A student sets up two sealed flasks: one with oxygen and methane, and one with oxygen and nitrogen dioxide. Both are exposed to UV light. Which flask would most likely contribute to the formation of ground-level ozone?

Both flasks equally Neither flask Only the methane flask Only the nitrogen dioxide flask

Quiz: Chemistry - Maintaining Air Quality