Chemistry AS Chains,Energy & Resources Key Definitions

All of the key definitions



A compound consisting of hyrdrogen and carbon only

1 of 20

Homologous Series

A series or organic compounds that have the same functional group but each successive member differing by CH2

2 of 20

Functional Group

A group of atoms responsible for the characteristic reactions of a compound

3 of 20


Contains single bonds only

4 of 20


Consists of at least one multiple carbon to carbon bond

5 of 20

Empirical Formula

The simplest whole number ratio of an atoms of each element present in a compound

6 of 20

Molecular Formula

The actual number of atoms of each element in a molecule

7 of 20

Structural Isomer

A compound with the same molecular formula but a different structural formulae

8 of 20


Compounds with the same structural formula but a different arrangement of atoms in space

9 of 20

E/Z Isomerism

An example of stereoisomerism, in terms of restricted rotation about a double bond and the requirement for two different groups to attach to each carbon of the C=C group

10 of 20

Cis-Trans Isomerism

A special case of E/Z isomerism in which two of the constituent groups are the same

11 of 20

Fractional Distillation

The seperation of a liquid mixture into fractions with different boiling points

12 of 20

Catalytic Cracking

The breaking down of longer chained saturated hyrdocarbons into more useful alkanes (shorter chained) and alkenes

13 of 20


A fuel which is derived from recently living material such as plants and animal waste

14 of 20

Curly Arrow

The movement of an electron pair, showing either the breaking or formation of a covalent bond

15 of 20


A species with an unpaired electron

16 of 20

Homolytic Fission

The breaking of a covalent bond where the shared pair of electrons are split equally forming two radicals

17 of 20

Heterolytic Fission

The breaking of a covalent bond where the shared pair of electrons split unequally to form a cation and an anion

18 of 20


Electron pair acceptor

19 of 20


Electron pair donor

20 of 20




really, really useful to see them all in one place - thanks! 

Similar Chemistry resources:

See all Chemistry resources »See all Energetics resources »