Question

The major components of the atmosphere are: (a) \(\mathrm{CO}_{2}\) and \(\mathrm{N}_{2}\) (b) \(\mathrm{O}_{3}\) and \(\mathrm{SO}_{2}\) (c) \(\mathrm{CO}\) and \(\mathrm{CO}_{2}\) (d) \(\mathrm{N}_{2}\) and \(\mathrm{O}_{2}\)

Short answer

The major components of the atmosphere are \\ \\ ext{(d) N}_2 \\ \\ ext{and O}_2.

Step-by-step solution

Understanding the Problem

We need to find out which of the given options best represents the major components of Earth's atmosphere.

Listing the Main Atmospheric Gases

The Earth's atmosphere is primarily composed of ext{nitrogen} ( ext{N}_2) and ext{oxygen} ( ext{O}_2), making up approximately 78% and 21% of the atmosphere, respectively.

Analyzing Each Option

Compare each option to the major atmospheric components: - (a) Carbon dioxide ( ext{CO}_2) and nitrogen ( ext{N}_2): ext{CO}_2 is only a trace gas. - (b) Ozone ( ext{O}_3) and sulfur dioxide ( ext{SO}_2): Both are trace gases. - (c) Carbon monoxide ( ext{CO}) and carbon dioxide ( ext{CO}_2): Again, both are trace gases. - (d) Nitrogen ( ext{N}_2) and oxygen ( ext{O}_2): These are the two most abundant gases in the atmosphere.

Selecting the Correct Option

The correct option is (d) ext{N}_2 and ext{O}_2 because these two gases are the primary components of the atmosphere.

Key concepts

Nitrogen

Nitrogen is the most abundant gas in Earth's atmosphere, making up about 78% of the air we breathe. It is a colorless, odorless gas that plays a crucial role in maintaining life on our planet. Although we do not breathe in nitrogen directly in the way we do oxygen, it is essential for various biological processes.
One of the primary roles of nitrogen is in the nitrogen cycle, where nitrogen is converted into different chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems. This cycle is important for the production of amino acids, proteins, and nucleic acids, which are building blocks for life.
Here are a few key points about nitrogen:

• Essential for plant growth and development
• Integral for synthesizing amino acids
• Fosters healthy ecosystems

Despite its abundance, nitrogen must be converted into more reactive forms (like ammonia) through processes like fixation before it can be used by most living organisms. This conversion process is typically carried out by certain bacteria in the soil and roots of plants, as well as through industrial methods used in fertilizers.

Oxygen

Oxygen is the second most abundant gas in the Earth's atmosphere, comprising about 21%. It is a critical component for most life forms as it is essential for respiration, the process by which organisms release energy from food.
Oxygen in the atmosphere is largely credited to photosynthesis, a process where plants, algae, and some bacteria convert carbon dioxide and water into glucose and oxygen, using sunlight. This not only provides food for the plants themselves but also releases oxygen as a byproduct, enriching our atmosphere with this essential gas.
Here are some important aspects of oxygen:

• Vital for respiration and energy production in cells
• Supports combustion (fire)
• Helps regulate carbon dioxide levels through the carbon cycle

Remember, oxygen plays a pivotal role in supporting life, but it also has reactive properties. It can form compounds with almost all elements, and is involved in rusting (oxidation) processes as well as in the burning of fuels.

Trace Gases

While nitrogen and oxygen dominate the atmosphere, trace gases make up a very small portion of it but play significant roles in the environment. These trace gases include carbon dioxide, ozone, methane, and others, each with a specific purpose or effect.
**Carbon Dioxide (CO₂)** is involved in the greenhouse effect, which helps regulate Earth's temperature by trapping heat in the atmosphere. Though only about 0.04% of the atmosphere, changes in CO₂ levels can have a significant impact on global climate patterns.
**Ozone (O₃)** is crucial in the stratosphere as it forms the ozone layer that protects life by absorbing harmful ultraviolet radiation from the sun. However, at ground level, ozone can be a pollutant that harms respiratory health.
Here are a few points to consider about trace gases:

• Play a role in climate change and weather patterns
• Affect air quality and health
• Can be both beneficial and harmful depending on their concentration and location

Despite their small concentration, trace gases are a key focus in environmental science because of their outsized impact on climate and living organisms.