Earth Science Multiple-Choice Questions

Which gas was nearly absent in the Earth’s early atmosphere?

• Oxygen

• Methane

• Carbon dioxide

• Water vapor

Answer explanation

Oxygen was nearly absent in the Earth's early atmosphere, which was primarily composed of gases like methane, carbon dioxide, and water vapor. The significant presence of oxygen developed later due to photosynthetic organisms.

Which process naturally removes carbon dioxide from the atmosphere?

• Respiration

• Photosynthesis

• Combustion

• Melting

Answer explanation

Photosynthesis is the process by which plants convert carbon dioxide and sunlight into glucose and oxygen, effectively removing carbon dioxide from the atmosphere. The other options do not remove CO2.

What is climate best described as?

• Daily changes in wind and temperature

• Long-term weather pattern of a region

• A prediction of next week’s weather

• A temporary change in humidity

Answer explanation

Climate is best described as the long-term weather pattern of a region, encompassing average conditions over extended periods, unlike daily changes or short-term predictions.

What process contributes the most carbon dioxide from human activity?

• Breathing

• Using air conditioners

• Burning fossil fuels

• Drinking soda

Answer explanation

Burning fossil fuels, such as coal, oil, and natural gas, releases the most carbon dioxide from human activities. This process significantly contributes to greenhouse gas emissions, unlike breathing or using air conditioners.

What is a major environmental consequence of burning fossil fuels?

• Earthquakes

• Ozone production

• Increased rainfall

• Greenhouse gas emissions

Answer explanation

Burning fossil fuels releases carbon dioxide and other greenhouse gases into the atmosphere, contributing to climate change. This makes 'greenhouse gas emissions' the major environmental consequence of fossil fuel combustion.

The main function of the ozone layer is to block…

• Sound waves

• Radio signals

• UV radiation

• Heat from the Earth

Answer explanation

The ozone layer primarily functions to block UV radiation from the sun, protecting living organisms on Earth from harmful effects such as skin cancer and cataracts. Therefore, the correct answer is UV radiation.

The greenhouse effect helps to…

• Keep Earth’s temperature stable

• Reflect heat into space

• Eliminate global warming

• Form clouds

Answer explanation

The greenhouse effect is crucial for maintaining a stable temperature on Earth by trapping heat in the atmosphere. This process prevents extreme temperature fluctuations, making the planet habitable.

Which of the following is a greenhouse gas?

• Argon

• Helium

• Nitrogen

• Methane

Answer explanation

Methane is a potent greenhouse gas that traps heat in the atmosphere, contributing to global warming. In contrast, argon, helium, and nitrogen are not greenhouse gases as they do not significantly absorb infrared radiation.

Which energy source is not renewable?

• Solar

• Wind

• Biomass

• Natural gas

Answer explanation

Natural gas is a fossil fuel and is not renewable, unlike solar, wind, and biomass, which are sustainable energy sources that can be replenished naturally.

What is a benefit of recycling materials like aluminum?

• It releases less methane

• It requires more mining

• It reduces energy use

• It causes acid rain

Answer explanation

Recycling aluminum significantly reduces energy use compared to producing new aluminum from raw materials. This is because recycling requires less energy for processing, leading to lower overall energy consumption.