OCR GCSE Chemistry B Key Terms

Any physical or digital model that illustrates the three-dimensional arrangement of particles in a substance.

The exact margin of error associated with a measurement, usually based on the resolution of the equipment.

The process by which matter takes in radiation energy, which typically leads to an increase in its internal thermal energy.

A downward dip in a spectroscopy chart representing the specific frequency of radiation absorbed by a chemical bond's vibration.

How close a measurement result is to the true or acceptable value.

A substance that releases hydrogen ions when dissolved in water, resulting in a pH of less than 7.

The amount of acid solute dissolved in a given volume of water, typically measured in mol/dm³.

An oxide, typically formed by a non-metal, that reacts with bases to form a salt and water, or dissolves in water to form an acidic solution.

The property of a solution caused by a higher concentration of hydrogen ions than hydroxide ions.

Precipitation with a low pH (typically below 5.5) caused by sulfur dioxide and nitrogen oxides dissolving in cloud water.

A measure of the degree of ionisation or dissociation of an acid in water.

The minimum amount of energy required for reactant particles to collide and react successfully.

The minimum amount of energy that reacting particles must possess to react when they collide.

The minimum amount of energy that particles must have to react when they collide.

The component in a medical formulation responsible for the desired effect or treatment.

The specific region on an enzyme where the substrate binds and the chemical reaction occurs.

Specific locations on the surface of a catalyst where reactant molecules can bind and undergo a chemical reaction.

The mass of product actually obtained from a real-world chemical reaction.

A long-chain molecule formed when many identical alkene monomers join together without any other product being formed.

A chemical reaction where many small monomer molecules join together to form a long polymer chain with no other products.

A reaction where two or more molecules combine to form a single larger molecule, typically occurring across a carbon-carbon double bond.

How well a substance sticks to a surface.

Changes to the way people work, such as safety protocols or limiting exposure time, to reduce risk.

The process where reactant molecules stick to the active sites on the surface of a solid catalyst.

The process of bubbling or spraying air through water to release dissolved gases, oxidise minerals, and provide oxygen for aerobic bacteria.

Microscopic organisms that decompose dead organic matter while consuming dissolved oxygen through aerobic respiration.

The natural attraction or intermolecular "stickiness" a substance has for the stationary phase.

The process of planting trees on land that has not previously contained forests to create new carbon sinks.

A measure of the amount of crop yield produced from a given area of land.

The extremely thin physiological membrane in the lungs that nanoparticles can cross to enter the bloodstream.