definitions

Question 1

Relative atomic mass

Answer 1

The weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12

Question 2

Molecular or complex ions

Answer 2

Groups of covalently bonded atoms that can lose or gain electrons to form ions

Question 3

Molar gas volume

Answer 3

The volume per mole of a gas (dm3mol-1)

Question 4

Covalent bond

Answer 4

Strong electrostatic attraction between a shared pair of electrons

Question 5

Dative covalent bond

Answer 5

A type of covalent bond in which both of the electrons in the shared pair come from one atom

Question 6

Ionic bond

Answer 6

The electrostatic attraction between two oppositely charged ions

Question 7

Metallic bond

Answer 7

Electrostatic attraction between metal cations and delocalised electrons

Question 8

Homologous series

Answer 8

Family of compounds with the same functional group but each successive member differs by CH2

Question 9

Atomic orbital

Answer 9

A region of space that can contain 2 electrons with opposite spins

Question 10

Sub-shell

Answer 10

All the orbitals of the same type within one shell

Question 11

Standard solution

Answer 11

A solution of known concentration

Question 12

Structural isomers

Answer 12

Compounds with the same molecular formula, but different structural formula

Question 13

Stereoisomers

Answer 13

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

Question 14

Electrophile

Answer 14

electron pair acceptor

Question 15

Nucleophile

Answer 15

electron pair doner

Question 16

Substitution Reaction

Answer 16

When an atom or group of atoms is replaced with a different atom or group of atoms

Question 17

Hydrocarbon

Answer 17

Contains hydrogen and carbon only

Question 18

Aliphatic

Answer 18

A compound containing carbon and hydrogen joined together in straight or branched chains or non-aromatic rings

Question 19

Alicyclic

Answer 19

An aliphatic compound arranged in non-aromatic rings with or without side chains

Question 20

Aromatic

Answer 20

A compound containing a benzene ring

Question 21

Functional group

Answer 21

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

Question 22

E/Z isomerism

Answer 22

An example of stereoisomerism

Occurs due to restricted rotation about C=C

Occurs if the groups attached to each carbon atom of the C=C group are different

Question 23

cis/trans isomerism

Answer 23

A special type of e/z isomerism in which two of the substituent groups attached to each carbon atoms of the C=C bond are the same

Question 24

Oxidation

Answer 24

loss of electrons

Question 25

Reduction

Answer 25

gain of electrons

Question 26

Isotope

Answer 26

Atoms of the same elements with the same number of protons but a different number of neutrons

Question 27

Permanent dipole

Answer 27

The attractive force between two neighbouring molecules

Question 28

Catalyst

Answer 28

Changes the rate of reaction but is chemically unchanged by lowering the activation energy and providing an alternative reaction pathway

Question 29

Activation energy

Answer 29

Minimum energy required for the reaction to start

Question 30

London forces

Answer 30

A temporary attractive force due to the formation of temporary dipoles in a nonpolar molecule.

Question 31

Electronegativity

Answer 31

The ability of an atom in a covalent bond to attract the shared pair of bonding electrons towards itself

Question 32

Biodegradable

Answer 32

Can be broken down by microbes

Question 33

Photodegradable

Answer 33

Can be broken down by light

Question 34

First ionisation energy

Answer 34

The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ions

Question 35

Periodicity

Answer 35

A repeating trend in physical and chemical properties across the periods of the periodic table

Question 36

Acid

Answer 36

A substance that donates protons when dissolved in water

Question 37

Disproportionation

Answer 37

When the same element is oxidised and reduced in a reaction

Question 38

Redox reaction

Answer 38

When oxidation and reduction happen in the same reaction

Question 39

Oxidation number

Answer 39

Total number of electrons an atom gains or loses to form a chemical bond

Question 40

Displacement reaction

Answer 40

The more reactive halogen will act as the oxidising agent and oxidise and displace the less reactive halogen

Question 41

Saturated

Answer 41

single carbon-carbon bonds only

Question 42

Unsaturated

Answer 42

the presence of multiple carbon-carbon bonds, including C=C , C≡C and aromatic rings