Science Revision

A substance that releases hydrogen ions (H+) in water. Has a pH less than 7 (1-7), with 1 being strongly acid and 6 being weakly acidic.

Rain which has acids dissolved within it such as nitric acid and sulphuric acid due to pollution.

A reaction that uses oxygen to release the energy stored in glucose.

A soluble base. Releases hydroxide ions (OH-) into water or creates through reaction with water, and has a pH greater than 7, with 14 being strongly alkaline.

A negatively charged ion.

A solution involving water (aquatic).

The smallest component of an element that contains all of the properties or characteristics of that element.

The number of protons in the nucleus of an atom.

Each side of a chemical equation has the same number of each type of atom.

Chemical opposite of an acid. Neutralizes an acid to form a salt. pH greater than 7, with 14 being the strongest

A positively charged ion.

A substance is caustic if it is able to cause corrosion.

A shorthand way of showing which elements are present in a substance, and the relative numbers of its atoms.

Theory used to explain reaction rate in terms of collisions between particles.

A rapid reaction with oxygen that releases energy, often in the form of heat or light.

Substance made up of more than one type of atom; the atoms are chemically joined.

Atoms are neither created nor destroyed in a chemical reaction, they are only rearranged.

In relation to acids – The split of hydrogen ions from the rest of an acid in a solution. The strength of an acid is determined by the amount of dissociation.

• Sub-atomic particle, located outside the nucleus with negligible mass and a negative
• electric charge (e-).

Substance made up of only one type of atom.

A chemical reaction that absorbs energy.

A chemical reaction that releases energy

A type of sugar produced by photosynthesis (C⁶H¹²O⁶).

A positively charged hydrogen atom (H⁺); released when acids are added to water.

A negatively charged ion (OH^-); released when bases are added to water.

A substance that changes colour depending upon the pH of the solution to which it is added.

Molecule with an overall electrical charge, gained through the loss or gain of electrons.

A common indicator that turns red in the presence of acids and blue in the presence of bases.

The number of protons and neutrons in the nucleus of an atom.

Having no charge (e.g. neutron). An atom is neutral if the number of protons and electrons is equal.

The reaction where an acid and a base react to form a salt and water.

A particle found in the nucleus of an atom. Has mass but no electrical charge.

The positively charged center of an atom which contains the majority of the mass.

A scientific theory that states that every substance consists of tiny particles.

Scale for measuring the acidity  of a solution. The more acidic the solution the lower the number of the scale. pH scale is from 0 to 14 with acids having a pH less than 7 and bases having a pH greater than 7.

Endothermic reaction that takes place in green plants. Uses energy from sunlight to combine water and carbon dioxide and produces glucose and oxygen.

A substance formed in a chemical reaction

The speed of a reaction. Measured in amount per time e.g. g/s

Chemical that is used up in a reaction. 

Any compound formed by a metal taking the place of the hydrogen ion in an acid.

A way of writing down the reactants and products of chemical reactions in words, (e.g. magnesium + hydrochloric acid → magnesium chloride + hydrogen).

Hydrogen + salt

Salt + water

carbon dioxide + water + salt