No Year 7

Element

A substance that can’t be broken down into other substances.

Atom

The smallest building block of an element.

Properties

Characteristics of a substance.

Molecule

More than one atom joined together with chemical bonds.

Chemical Bonding

Forces between atoms that make them strongly joined to each other.

Combustion

A fast chemical reaction between a fuel and oxygen, also known as burning.

Oxides

Chemical compounds which include oxygen as well as other element(s).

Bases

Chemical compounds which can take up hydrogen ions.

Basic

A solution where the pH is higher than 7.

Acidic

A solution where the pH is lower than 7.

pH value

A measurement of how acidic or how alkaline a solution is.

Indicator

A substance used to show what pH value a solution has.

Neutral

A solution with a pH of 7.

pH scale

A scale from 1 to 14 which shows how acidic or alkaline a solution is.

Acids

Chemical substances which can give hydrogen ions.

Chemical Reaction

A process where atoms rearrange and join together to form new substances.

Reactants

The substances at the start of a chemical reaction.

Products

The substances after the chemical reaction.

Exothermic Reaction

A reaction that transfers energy to the surroundings, often shown by an increase in temperature.

Endothermic Reaction

A reaction that absorbs energy from the surroundings, usually resulting in a temperature decrease.

Neutralisation

A chemical reaction where an acid and a base react to form water and salt, and the pH approaches 7.

Dilute

A solution that has had water added, reducing its concentration.

Concentrated

A solution with a high amount of solute per volume of solvent.

Litmus Paper

A tool that changes color to indicate whether a solution is acidic or alkaline.

Universal Indicator

A pH indicator that provides a color range to indicate how strong an acid or alkaline solution is.