Earth's Atmosphere Composition

Composition of Earth's Atmosphere

• Earth's atmosphere is composed of various gases, primarily nitrogen and oxygen, with trace gases.
• Nitrogen makes up 78.08% of total volume and contributes 79.11 kPa to atmospheric pressure.
• Oxygen makes up 20.95% of total volume and contributes 21.22 kPa to atmospheric pressure.
• Argon makes up 0.93% of total volume and contributes 0.95 kPa to atmospheric pressure.
• Trace gases contribute a small percentage of total volume.

Composition of Dry Air

• Dry air is air that doesn't contain water vapor.
• The partial pressure of each gas in dry air is proportional to its volume percentage.
• For example, the partial pressure of nitrogen is 79.11 kPa, calculated as (78.08 ÷ 100%) × 101.32 kPa.

Trace Gases

• Trace gases include carbon dioxide, neon, helium, and methane.
• Carbon dioxide makes up 0.04% of total volume.
• Neon makes up 0.0018% of total volume.
• Helium makes up 0.0005% of total volume.
• Methane makes up 0.00017% of total volume.

Earth's Atmosphere Composition

• The Earth's atmosphere is made up of various gases, primarily nitrogen and oxygen.
• Trace gases make up a smaller portion of the atmosphere.
• Each gas contributes to the total atmospheric pressure, known as partial pressure.

Composition of Dry Air

• Dry air, devoid of water vapor, is predominantly composed of Nitrogen (78.08% by volume), followed by Oxygen (20.95% by volume).
• Argon makes up a smaller percentage at 0.93%.
• Carbon dioxide, a trace gas, contributes to 0.04% of the air volume.

Partial Pressure

• The partial pressure of a gas is proportional to the gas's percentage of the total volume.
• For instance, nitrogen contributes 79.11 kPa to the total atmospheric pressure, which is calculated by multiplying its volume percentage (78.08%) by the total atmospheric pressure (101.32 kPa).
• Carbon dioxide contributes 0.04 kPa to the total atmospheric pressure.