Gases in Earth's Atmosphere

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Atmosphere Noun

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[at-muh-sfeer]

Back

Atmosphere

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The mixture of gases surrounding the Earth, held in place by gravity and primarily composed of nitrogen and oxygen.

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Example: This diagram shows Earth's atmosphere is a mix of gases, with the largest part being nitrogen (78%) and the next largest being oxygen (21%).

Front

Partial Pressure Noun

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[par-shuhl presh-er]

Back

Partial Pressure

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The pressure exerted by a single gas within a mixture, as if it alone occupied the entire volume.

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Example: This diagram shows that the total pressure of a gas mixture (right) is the sum of the individual pressures (partial pressures) of each gas (left and middle).

Front

Dalton's Law Noun

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[dawl-tuhns law]

Back

Dalton's Law

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A scientific principle stating the total pressure of a gas mixture is the sum of each individual gas's partial pressure.

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Example: The total pressure of a gas mixture, like air, is equal to the sum of the pressures of each individual gas in the mixture.

Front

Nitrogen Narcosis Noun

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[nahy-truh-juhn nahr-koh-sis]

Back

Nitrogen Narcosis

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A drowsy, intoxicating state caused by breathing nitrogen under high pressure, which commonly affects deep-sea divers.

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Example: As a diver descends, increasing water pressure forces more gas from their breathing tank to dissolve into the body, which is the physical process that leads to nitrogen narcosis.

Front

Diffusion Noun

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[dih-fyoo-zhuhn]

Back

Diffusion

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The net movement of molecules from a region of higher concentration to one of lower concentration until equilibrium is reached.

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Example: This diagram shows particles moving from an area of high concentration to an area of low concentration, passing through a semi-permeable membrane.

Front

Equilibrium Noun

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[ee-kwuh-lib-ree-uhm]

Back

Equilibrium

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A state of balance where opposing forces or influences result in a stable system with uniform and constant concentrations.

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Example: This image shows balanced forces on a car. The forward driving force is equal to the backward friction and air resistance, representing a state of equilibrium.

Front

Kinetic Energy Noun

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[ki-net-ik en-er-jee]

Back

Kinetic Energy

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The energy an object possesses due to its motion, which is dependent on its mass and velocity.

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Example: This image shows a soccer ball in motion after being kicked, illustrating that kinetic energy is the energy an object has due to its movement.

Front

Effusion Noun

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[ih-fyoo-zhuhn]

Back

Effusion

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The process by which gas particles under pressure escape from a container through a very small opening.

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Example: This diagram shows effusion, where gas particles escape from a container through a tiny pinhole into an empty (evacuated) chamber.

Front

Graham's Law Noun

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[grey-uhms law]

Back

Graham's Law

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A principle stating a gas's effusion rate is inversely proportional to the square root of its molar mass.

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Example: This image shows that lighter gas particles (Helium) and heavier gas particles (Oxygen) have different masses, which explains why they diffuse at different rates.

Front

Molar Mass Noun

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[moh-ler mas]

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Molar Mass

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The mass of one mole of a substance, which is typically expressed in units of grams per mole (g/mol).

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Example: This image shows that the molar mass of a molecule (like water, H₂O) is calculated by adding the individual atomic masses of its atoms.