S2 Chemistry: Gases and the Environment - Vocabulary Flashcards

Vocabulary practice flashcards generated from the Gases and the Environment unit notes, covering gas properties, test methods, chemical terminology, air pollution, global warming, acid rain, and environmental indicators.

Reactant

A chemical used up in a reaction, appearing on the left hand side of the reaction arrow.

Product

A chemical made in a reaction, appearing on the right hand side of the reaction arrow.

Oxygen ($O_2$)

A gas composing $20\%$ of dry air that is essential for burning and breathing; its chemical test is that it relights a glowing splint.

Carbon dioxide ($CO_2$)

A gas composing $0.03\%$ of dry air used in fizzy drinks and fire extinguishers; its chemical test is that it turns lime water cloudy.

Nitrogen ($N_2$)

A gas composing $78\%$ of dry air used in fertilisers and freezing fresh food; it is too unreactive to produce a result in standard splint or lime water tests.

Hydrogen ($H_2$)

A gas composing $0\%$ of dry air used in weather balloons and fertilisers; its chemical test is that it gives a squeaky pop with a burning splint.

Argon

A gas composing $1\%$ of dry air, used in light bulbs and arc welding.

Carbon monoxide

An air pollutant that is a poisonous gas with no smell.

Sulfur dioxide

An air pollutant gas that dissolves in rain clouds to form acid rain, which can erode stone and kill plants.

Soot

An air pollutant produced during burning that makes everything very dirty.

Greenhouse Effect

The natural warming effect produced mainly by carbon dioxide and methane, without which the Earth would be $33\,^\circ\text{C}$ colder.

Global Warming

The increasing trend in global average temperatures caused by atmospheric changes, leading to melting ice caps, rising sea levels, and expanding deserts.

Acid Rain

Rainfall rendered acidic primarily by sulfur dioxide and nitrogen oxide, causing building erosion, leaf damage, soil nutrient loss, and lower water pH that kills aquatic animals.

Lichen

Natural bioindicators used to measure air pollution levels based on species tolerance: bushy lichens require clean air, leafy lichens tolerate low pollution, crusty lichens tolerate higher pollution, and absence indicates heavy sulfur dioxide pollution.

Photosynthesis

The process where green plants convert carbon dioxide and water into glucose and oxygen, helping balance respiration in the carbon cycle.

Respiration

The process in living organisms where carbohydrates (glucose) are broken down by reaction with oxygen to release energy, carbon dioxide, and water.

Atom

The smallest part of an element.

Compound

A substance in which two or more elements are chemically joined together (e.g. $MgO$).

Element

A substance that cannot be broken down chemically.

Fuel

A substance that releases heat energy when burned.