Air Around Us_11

What percentage of the atmosphere is formed by oxygen?

• 32%

• 78%

• 21%

• 15%

What is the term used for the circulation and recycling of oxygen within the biosphere?

• Water cycle

• Carbon cycle

• Oxygen cycle

• Nitrogen cycle

Which of the following is not a form in which oxygen is found?

• Water (H2O)

• Carbon dioxide (CO2)

• Molecular oxygen (O2)

• Carbon monoxide (CO)

What is the process in which oxygen is released?

• Corrosion

• Photosynthesis

• Respiration

• Combustion

What are microbes that use oxygen for respiration called?

• Viruses

• Bacteria

• Aerobes

• Anaerobes

What is the importance of oxygen in the biosphere?

• Synthesis of proteins, carbohydrates, and fats

• Formation of ozone (O3)

• Used in various chemical reactions

• All of the above

What is produced from oxygen through various atmospheric processes?

• Carbon monoxide (CO)

• Molecular oxygen (O2)

• Water (H2O)

• Ozone (O3)

What is the term used for the lithosphere and hydrosphere where oxygen is present?

• Biosphere

• Geosphere

• Atmosphere

• Cryosphere

What is the term used for the components of the oxygen cycle that are not living?

• Biotic components

• Inorganic compounds

• Abiotic components

• Organic compounds

What is the term used for the process in which oxygen is used up?

• Photosynthesis

• Respiration

• Decomposition

• Combustion