N5 DEFINITIONS

Question 1

Electrolysis

Answer 1

Electrolysis is the decomposition of an ionic compound into its elements using electricity

Question 2

Decomposition

Answer 2

Decomposition is when a single compound breaks down into two or more elements or new compounds

Question 3

Ionic bonding

Answer 3

The electrostatic attraction between positive and negative ions

Question 4

Metallic bonding

Answer 4

The electrostatic force of attraction between positively charged ions and delocalised electrons

Question 5

Covalent bonding

Answer 5

A shared pair of electrons between atoms of two non-metal elements

Question 6

Combustion

Answer 6

When a substance reacts with oxygen to release heat energy

Question 7

Simple cell

Answer 7

Two different metal electrodes in an electrolyte

Question 8

Ion-bridge

Answer 8

Used to link half-cells, ions can move across the bridge to complete an electrical circuit

Question 9

Displacement

Answer 9

When a metal higher up in the electrochemical series displaces the ions of the lower down metal

Question 10

Chemical change

Answer 10

A change that is usually non reversible and produces a new substance

Question 11

Physical change

Answer 11

A change from one state to another without a change in chemical composition

Question 12

Precipitation

Answer 12

An insoluble solid is formed

Question 13

Effervescence

Answer 13

Gas is given off

Question 14

Catalyst

Answer 14

A substance that speeds up the rate of reaction and is unchanged throughout

Question 15

Molecule

Answer 15

A group of atoms held together by covalent bonds

Question 16

Diatomic molecule

Answer 16

A molecule only containing 2 atoms

Question 17

Ion

Answer 17

A charged particle

Question 18

Equilibrium

Answer 18

A small proportion of water breaking down into H+ and OH- ions and then reacting again to produce water.

Question 19

Spectator ion

Answer 19

Ions that are present in the reaction but are unchanged by the reaction so must be the same state from start to end

Question 20

Neutralisation

Answer 20

When an acid and base neutralise eachother to produce a salt and water

Question 21

Ore

Answer 21

A rock that contains metal

Question 22

Compound

Answer 22

Chemical substance composed of molecules

Question 23

Extraction of metals

Answer 23

Metals ions are reduced, forming metal atoms

Question 24

Alloy

Answer 24

A mixture of two elements

Question 25

Ion-electron equation

Answer 25

A half equations. Either oxidation or reduction, which in combination with the opposite type - can be part of a complete redox equation

Question 26

Native

Answer 26

Term given to unreactive metals such as gold or platinum which can be found in their pure states

Question 27

Electrolyte

Answer 27

Electrically conducting solutions containing ions

Question 28

Polymers

Answer 28

Long chain molecules formed by joining together a large number of monomers

Question 29

Addition polymerisation

Answer 29

Unsaturated monomers joining, forming a polymer

Question 30

Fertiliser

Answer 30

Substances which restore elements that are essential for healthy plant growth to the soil

Question 31

Radioactive decay

Answer 31

Changes in the nuclei of atoms

Question 32

Beta particle

Answer 32

Electrons ejected from the nucleus of an atom

Question 33

Gamma ray

Answer 33

Electromagnetic waves emitted from within the nucleus of an atom

Question 34

Half-life

Answer 34

The time taken for half of the nuclei of a particular isotope to decay