Chemistry key terms

A device in which chemical reactions produce a voltage.

A change in which one or more new substances are formed by a chemical reaction.

A combination of element symbols and numbers showing which elements a substance contains and their fixed proportions.

Describes a substance that is very unlikely to take part in chemical reactions.

Able to resist reaction with other substances.

Having the same chemical identity and composition as before.

Features that describe how a substance behaves in chemical reactions, such as the kinds of compounds it forms.

A characteristic describing how a substance reacts to form other substances.

A process in which atoms are rearranged to form one or more new substances.

A measure of how readily a substance undergoes chemical reactions.

A drawing or model that stands for a chemical structure while showing selected features of it.

Any atom, molecule, ion or formula unit represented in a chemical calculation or equation.

The arrangement of atoms and the bonds connecting them in a substance.

A one- or two-letter abbreviation used to represent an element and its atoms.

A procedure in which a sample is treated in a specified way and the resulting observation is used as evidence about its identity.

Adding chlorine to water to kill harmful microorganisms.

A greenish-yellow, toxic gas with the formula Cl₂.

The green pigment that absorbs the light energy needed for photosynthesis.

The pattern of spots produced when substances have been separated by chromatography.

A technique used to separate a mixture of soluble substances and obtain information that can help identify them.

The process of placing substances into groups by comparing characteristic properties or structures.

The long-term pattern and average of weather conditions in a region or across the Earth.

A lasting change in climate patterns, including average temperature, rainfall and the frequency or intensity of extreme weather.

Action taken to limit climate change by reducing greenhouse-gas emissions or increasing their removal from the atmosphere.

Information about climate variables, such as temperature or atmospheric composition, collected over time or across locations.

A factor that changes the Earth's energy balance and therefore tends to warm or cool the climate.

A simplified representation of the climate system used to investigate past changes or project possible future changes.

A container or apparatus from which reactants and products cannot escape.

Particles with diameters from 2500 nm to 10,000 nm, often described as dust.

A number written before a chemical formula to show its relative amount in a balanced equation.