Composition and Properties of Air

Major Components:
- Nitrogen (N2) - ~78%
- Oxygen (O2) - ~21%
- Argon (Ar) - ~0.93%
- Carbon Dioxide (CO2) - ~0.04%
- Trace gases - Includes neon, helium, methane, and others.

Troposphere:
- Lowest layer; weather occurs here.
- Extends up to ~8-15 km.
Stratosphere:
- Contains the ozone layer; protects from UV radiation.
- Extends from ~15 km to ~50 km.
Mesosphere:
- Middle layer; meteors burn up here.
- Extends from ~50 km to ~85 km.
Thermosphere:
- High temperatures; auroras occur here.
- Extends from ~85 km to ~600 km.
Exosphere:
- Outermost layer; satellite orbits.
- Extends from ~600 km to ~10,000 km.

Respiration: Essential for breathing and survival of aerobic organisms.
Combustion: Oxygen is necessary for combustion processes.
Weather and Climate: Air plays a key role in atmospheric dynamics and phenomena.

Air Pollutants: Includes particulate matter, carbon monoxide, sulfur dioxide, nitrogen oxides, and volatile organic compounds.
Health Effects: Poor air quality can lead to respiratory diseases, cardiovascular problems, and other health issues.

Regulatory Bodies: Organizations like the EPA set standards for air quality to protect public health and the environment.
Index: Air Quality Index (AQI) measures air pollution levels, providing a simple way to gauge air safety.

Wind: Movement of air caused by pressure differences; influenced by Earth's rotation (Coriolis effect).
Weather Patterns: High and low-pressure systems drive weather changes; fronts indicate transitions between air masses.

Major components include nitrogen (N2) at approximately 78%, oxygen (O2) at about 21%, argon (Ar) at nearly 0.93%, and carbon dioxide (CO2) at around 0.04%.
Trace gases, such as neon, helium, and methane, make up a minor portion of the atmosphere.

Air possesses weight and exerts pressure, impacting various physical processes.
Density of air declines with increasing altitude, affecting buoyancy and flight.
Temperature generally drops with height in the troposphere, influencing weather patterns.

Troposphere: The lowest atmospheric layer where weather phenomena occur, extending roughly 8-15 km above Earth's surface.
Stratosphere: Contains the ozone layer, essential for blocking harmful ultraviolet (UV) radiation, extending from about 15 km to 50 km.
Mesosphere: The middle layer where meteors incinerate upon entry, spanning approximately 50 km to 85 km.
Thermosphere: Characterized by high temperatures, it is where auroras take place, extending from about 85 km to 600 km.
Exosphere: The outermost atmospheric layer, hosting satellite orbits, ranging from about 600 km to 10,000 km above Earth.

Defined as the force exerted by air molecules on a surface per unit area.
Measured using a barometer with common units like Pascals and mmHg.
Air pressure decreases with altitude and is influenced by temperature and humidity variations.

Crucial for respiration in aerobic organisms, supporting life on Earth.
Oxygen is essential for combustion processes, affecting energy production and fire dynamics.
Air plays a key role in weather and climate, driving atmospheric dynamics and phenomena.

Common air pollutants include particulate matter, carbon monoxide, sulfur dioxide, nitrogen oxides, and volatile organic compounds.
Poor air quality can lead to serious health issues, including respiratory diseases and cardiovascular problems.

Regulatory bodies such as the EPA establish air quality standards to safeguard public health and the environment.
The Air Quality Index (AQI) serves as an accessible measure of air pollution, indicating safety levels for public awareness.

Wind results from air movement caused by pressure differences, significantly influenced by Earth's rotation, known as the Coriolis effect.
Weather patterns are shaped by high and low-pressure systems, with fronts marking transitions between different air masses.