arrow_backBack to Study Resources

Quiz Chapter 7: Air

10 questions · Form 1 Science Bab 7: Air

10 questions · plays in fullscreen

Full Question List & Answer Key

Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.

1. Which gas is released back into the atmosphere solely through the process of photosynthesis?

  1. Carbon dioxide
  2. Oxygen
  3. Nitrogen
  4. Water vapor
Show answer

Answer: B

Photosynthesis by green plants is the primary biological process that produces and releases oxygen into the air.

2. Why does covering a burning pan with a damp towel extinguish the fire?

  1. It removes the fuel source
  2. It cuts off oxygen supply and lowers heat
  3. It introduces carbon monoxide to stop burning
  4. It increases air circulation
Show answer

Answer: B

The wet towel creates a barrier that blocks oxygen gas from reaching the flame and absorbs heat energy.

3. What effect does haze have on the surrounding environment?

  1. Increases atmospheric oxygen level
  2. Reduces visibility and causes respiratory difficulties
  3. Prevents soil erosion
  4. Neutralizes acid rain
Show answer

Answer: B

Haze consists of suspended fine particulate matter like soot and dust, severely reducing visibility and triggering asthma/respiratory issues.

4. Which percentage accurately represents the proportion of Oxygen gas in clean dry air?

  1. 78%
  2. 21%
  3. 1%
  4. 0.03%
Show answer

Answer: B

Oxygen makes up approximately 21% of clean atmospheric air.

5. Why is carbon monoxide gas extremely dangerous to human health?

  1. It causes skin burns on contact
  2. It combines with hemoglobin in blood, reducing oxygen transport
  3. It destroys human lung tissue instantly
  4. It triggers severe allergic reactions on eyes
Show answer

Answer: B

Carbon monoxide binds strongly with hemoglobin to form carboxyhemoglobin, preventing red blood cells from carrying oxygen.

6. Which biological activity consumes oxygen gas from the air?

  1. Photosynthesis
  2. Respiration
  3. Transpiration
  4. Nitrogen fixation
Show answer

Answer: B

Cellular respiration in living organisms consumes oxygen to break down glucose and release energy.

7. Which process removes carbon dioxide from atmospheric air?

  1. Combustion of fossil fuels
  2. Decay of organic material
  3. Photosynthesis
  4. Volcanic eruption
Show answer

Answer: C

Photosynthesis is the sole natural process that absorbs carbon dioxide directly from the atmosphere.

8. Which practice directly reduces atmospheric air pollution caused by vehicle emissions?

  1. Open burning of garden waste
  2. Using public transportation or carpooling
  3. Increasing fossil fuel consumption in power stations
  4. Deforestation for agricultural land
Show answer

Answer: B

Utilizing public transportation or carpooling lowers the number of individual motor vehicles on roads, reducing exhaust emissions.

9. Which inert gas is used inside traditional electric light bulbs to prevent the filament from burning out?

  1. Argon
  2. Oxygen
  3. Carbon dioxide
  4. Hydrogen
Show answer

Answer: A

Argon is an unreactive noble gas used to fill filament light bulbs, protecting tungsten filaments from oxidation.

10. Which pollutant gas is primarily responsible for the depletion of the earth's ozone layer?

  1. Chlorofluorocarbons (CFCs)
  2. Carbon dioxide
  3. Sulfur dioxide
  4. Methane
Show answer

Answer: A

Chlorofluorocarbons (CFCs) release chlorine radicals that react with and break down protective ozone ($O_3$) molecules.

Sponsored