Set 4 | Important Environment and Sustainable Development MCQs

Correct Answer is C.

• In June 1992, Rio de Janeiro, Brazil hosted the first Earth Summit, which was formally called the United Nations Conference on Environment and Development (UNCED).
• World leaders, non-governmental organizations, and other interested parties convened at this historic event to talk about sustainable development and global environmental challenges.

Correct Answer is A.

• International conference held in Rio-de-Janeiro in 1992 was the United Nations Conference on Sustainable Development.  
• Held in Rio de Janeiro from June 3–14, 1992, the United Nations Conference on Environment and Development (UNCED), also referred to as the Rio de Janeiro Conference or the Earth Summit (Portuguese: ECO92, Cúpula da Terra), was a significant UN conference.
• The Earth Summit was established as a vehicle for post-Cold War member states to collaborate globally on development-related issues. Since sustainability-related problems are too big for individual member states to handle, the Earth Summit served as a forum for cooperation amongst member states.

Correct Answer is C.

• The atmosphere is a thin layer of gases that surrounds the Earth and is essential to both maintaining life on the planet and controlling its temperature. Its main constituents are nitrogen (approximately 78 percent) and oxygen (about 21 percent), with trace amounts of other gases including water vapor, argon, carbon dioxide, and neon.
• In order to protect life, the atmosphere must perform a number of vital tasks, including blocking UV and other dangerous solar radiation. maintaining a stable climate by controlling temperature through the greenhouse effect. Supplying necessary gases for photosynthesis and respiration, such as carbon dioxide.

Correct Answer is C.

• A mixture of gases makes up air. With trace amounts of other gases like argon, carbon dioxide, neon, and water vapor, its main constituents are nitrogen (about 78 percent) and oxygen (about 21 percent).
• This mixture is necessary for life on Earth because it contains other gases that are vital to many environmental processes as well as the oxygen required for respiration.

Correct Answer is D.

• The air around us is a mixture of gases, mainly Nitrogen and Oxygen, but containing much smaller amounts of water vapour, Argon, and Carbon Dioxide and very small amounts of other gases.

Correct Answer is B.

• Nitrogen and oxygen make up the majority of the air.
• Argon is the third most abundant gas but still makes up less than 1%.
• Carbon dioxide is present in small amounts but is significant for processes like photosynthesis and climate regulation.
• Water vapor content varies depending on location and weather conditions, contributing to the air’s humidity.

Correct Answer is C.

• These gases comprise a very small portion of the Earth’s atmosphere and are chemically non-reactive.
• Argon is the most abundant noble gas in the air, making up about 0.93% of the atmosphere by volume.
• Neon, helium, krypton, and xenon are present in trace amounts, each contributing a very small percentage.

Correct Answer is C.

• In the Earth’s atmosphere, the gas with the highest percentage is nitrogen (N2), which makes up about 78% of the atmosphere by volume.
• Abundance: Nitrogen is the most abundant gas in the atmosphere.
• Function: It is inert and helps dilute oxygen and other gases, preventing rapid combustion and supporting a stable environment for life.

Correct Answer is D.

• Nitrogen makes up approximately 78% of the Earth’s atmosphere by volume, making it the most abundant gas.
• Nitrogen is chemically inert, meaning it does not easily react with other substances under normal conditions. This stability is due to the strong triple bond between the nitrogen atoms in the N₂ molecule.
• Its lack of reactivity makes nitrogen a good diluent for other gases, preventing excessive reactions that could be harmful.
• Nitrogen helps to dilute oxygen in the atmosphere, which prevents rapid combustion and supports a stable environment.

Correct Answer is D.

• We need oxygen to survive and we depend on trees to provide this oxygen.
• To make food for themselves, trees go through a process known as photosynthesis where they take in carbon dioxide from the air and release oxygen back into the atmosphere.
• While the immediate effect would be a decrease in oxygen, carbon dioxide levels would increase due to the absence of photosynthesis, as decomposition and respiration processes continue to release CO₂ without being offset by plant absorption.