Composition and Properties of Air

Nitrogen: Approximately 78% of air; inert gas, non-reactive.
Oxygen: About 21%; essential for respiration and combustion.
Argon: Roughly 0.93%; a noble gas, non-reactive.
Carbon Dioxide: About 0.04%; crucial for photosynthesis; levels can vary with environmental factors.
Trace Gases: Includes neon, helium, methane, and hydrogen; found in very small amounts.

Density: Air density decreases with altitude; warmer air is less dense than cooler air.
Pressure: Atmospheric pressure decreases with elevation; measured in millibars or inches of mercury.
Temperature: Varies with altitude, affecting air density and pressure; the troposphere is the lowest layer where weather occurs.

Supports Life: Provides oxygen for respiration; carbon dioxide for photosynthesis.
Weather and Climate: Influences weather patterns and climate zones; transports moisture and heat.
Protection: The atmosphere protects the Earth from harmful solar radiation and meteoroids.

Wind: Caused by differences in air pressure; moves from high to low-pressure areas.
Currents: Large-scale movements, such as trade winds and jet streams, affect global weather patterns.
Convection: Warm air rises, cool air sinks; creates circulation patterns in the atmosphere.

Common Pollutants: Includes particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, and volatile organic compounds.
Sources: Emissions from vehicles, industrial processes, and natural events (e.g., wildfires).
Health Effects: Poor air quality can lead to respiratory problems, cardiovascular diseases, and other health issues.

Instruments: Barometers for pressure, anemometers for wind speed, hygrometers for humidity.
Air Quality Index (AQI): A measure used to communicate air quality levels to the public, indicating potential health impacts.

Nitrogen constitutes around 78% of the atmosphere, being an inert gas that does not react readily.
Oxygen makes up approximately 21% of air, vital for both human respiration and combustion processes.
Argon represents about 0.93% of the atmosphere; it is a noble gas known for its non-reactive properties.
Carbon Dioxide is present at roughly 0.04%; it is essential for photosynthesis and can fluctuate based on environmental changes.
Trace gases, such as neon, helium, methane, and hydrogen, are found in minimal quantities within the atmosphere.

Air density is inversely related to altitude; as altitude increases, density decreases, with warmer air being less dense than cooler air.
Atmospheric pressure diminishes with altitude, typically measured in millibars or inches of mercury, impacting weather patterns.
Temperature variations occur with altitude changes, affecting both air density and pressure; most weather phenomena occur in the troposphere, the lowest atmospheric layer.

Air is essential for sustaining life as it provides oxygen for animals and carbon dioxide for plant photosynthesis.
The atmosphere plays a crucial role in shaping weather conditions and climate zones, facilitating moisture and heat transport across the globe.
Protectively, the atmosphere shields the Earth from harmful solar radiation and meteoroids, contributing to environmental stability.

Wind is generated by differences in atmospheric pressure, flowing from areas of high pressure to areas of low pressure.
Large-scale air movements, such as trade winds and jet streams, significantly influence global weather systems.
Convection currents are formed as warm air rises and cool air descends, creating distinct circulation patterns within the atmosphere.

Common air pollutants include particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, and volatile organic compounds.
Major sources of pollution stem from vehicle emissions, industrial activities, and natural occurrences like wildfires.
Poor air quality can lead to various health issues, including respiratory ailments and cardiovascular diseases.

Instruments used to measure atmospheric conditions include barometers (for pressure), anemometers (for wind speed), and hygrometers (for humidity).
The Air Quality Index (AQI) serves as a crucial tool for communicating air quality levels to the public, helping to indicate potential health impacts associated with pollution.