Question

Arrange the following atmospheric components in order from most abundant to least abundant. 1. Argon 2. Nitrogen 3. Carbon dioxide 4. Oxygen

• A. 2, 4, 1, 3
• B. 4, 2, 1, 3
• C. 2, 1, 4, 3
• D. 2, 3, 4, 1

Answer 1

Answer:

A. 2, 4, 1, 3

Composition of Earth's Atmosphere: Abundance Explained

Understanding the relative abundance of gases in the Earth's atmosphere is fundamental for various scientific disciplines and a common topic in competitive examinations. Here's a breakdown of the main components from most to least abundant:

1. Nitrogen (N₂)

• Abundance: Approximately 78.09% of the dry atmosphere by volume.
• Characteristics: Nitrogen is a relatively unreactive gas in its atmospheric form.
• Importance: It is crucial for life, as it's a key component of amino acids, proteins, and nucleic acids.
• Exam Fact: Nitrogen fixation (conversion of atmospheric nitrogen into usable compounds) is carried out by certain bacteria and lightning. The nitrogen cycle is a vital biogeochemical cycle.

2. Oxygen (O₂)

• Abundance: Approximately 20.95% of the dry atmosphere by volume.
• Characteristics: Highly reactive gas, essential for respiration in most living organisms and for combustion processes.
• Importance: Produced primarily by photosynthesis from plants and phytoplankton.
• Exam Fact: The Great Oxidation Event, around 2.4 billion years ago, led to a significant increase in atmospheric oxygen, paving the way for the evolution of complex life.

3. Argon (Ar)

• Abundance: Approximately 0.93% of the dry atmosphere by volume.
• Characteristics: It is an inert (noble) gas, meaning it does not readily react with other substances.
• Importance: Used in various industrial applications like incandescent and fluorescent lighting, and as an inert shielding gas in welding.
• Exam Fact: Argon is the third most abundant gas in Earth's atmosphere, despite being a noble gas. It is primarily formed from the radioactive decay of Potassium-40.

4. Carbon Dioxide (CO₂)

• Abundance: Approximately 0.04% or 415 ppm (parts per million) by volume, though this value is increasing due to human activities.
• Characteristics: A greenhouse gas that plays a vital role in trapping heat in the atmosphere, contributing to the Earth's natural greenhouse effect.
• Importance: Essential for photosynthesis (plants use it to produce food).
• Exam Fact: Despite its small percentage, CO₂ has a significant impact on global climate. Its concentration has risen sharply since the industrial revolution, primarily due to the burning of fossil fuels and deforestation.

Other Trace Gases:

• The remaining fraction of the atmosphere includes tiny amounts of other gases like Neon (Ne), Helium (He), Methane (CH₄), Krypton (Kr), Hydrogen (H₂), and Xenon (Xe), along with variable amounts of water vapor (H₂O).
• Water vapor is highly variable (0-4%) and is also a significant greenhouse gas.