Key Words

Question 0

Molecular Formula

Answer 0

Actual number of atoms of each element in a molecule.

Question 1

Empirical Formula

Answer 1

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

Question 2

Heterolytic Fission

Answer 2

Breaking of a covalent bond, where both electrons go to one atom

Question 3

Homologous Series

Answer 3

A series of organic compounds having the same function group but with each successive member differing by CH2

Question 4

Structural Isomers

Answer 4

Compounds with the same molecular formula but different structural formula.

Question 5

Stereoisomers

Answer 5

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

Question 6

E/Z Isomerism

Answer 6

Restricted rotation about a double bond C=C.

Question 7

Homolytic Fission

Answer 7

Breaking of a covalent bond where 1 electron goes to each atom.

Question 8

Hydrocarbon

Answer 8

Compound containing only hydrogen and carbon.

Question 9

Enthalpy Change of Reaction

Answer 9

The enthalpy change that occurs in a reaction in the molar quantities in a chemical equation under standard conditions in standard states.

Question 10

Radical

Answer 10

Species with an unpaired electron.

Question 11

Activation Energy

Answer 11

Minimum energy required in order to start a reaction by breaking bonds.

Question 12

Enthalpy Change of Formation

Answer 12

The enthalpy change when a mole of compound is formed from its constituent elements in their standard states under standard conditions.

Question 13

Le Chatelier’s Principle

Answer 13

When a system is in dynamic equilibrium and is subject to a change, the position will shift to minimise change.

Question 14

Enthalpy Change of Combustion

Answer 14

The enthalpy change when one mole of substance is completely oxidised in an excess of oxygen under standard conditions and states.

Question 15

Catalyst

Answer 15

Speeds up a reaction without being consumed by the overall reaction.

Question 16

Relative Atomic Mass

Answer 16

The weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon 12.

Question 17

Relative Isotopic Mass

Answer 17

The weighted mean mass of an atom of an isotope relative to 1/12th of the mass of an atom of carbon 12.

Question 18

Relative Molecular Mass

Answer 18

The mass of one molecule relative to 1/12th of he mass of an atom of carbon 12.

Question 19

Relative Formula Mass

Answer 19

Weighted mean mass of a formula unit relative to 1/12th of a mass of an atom of carbon 12.

Question 20

Isotopes

Answer 20

Different neutron number. Same number of protons and electrons.

Question 21

Hydrated

Answer 21

Crystalline structure that contains water molecules.

Question 22

Anhydrous

Answer 22

Without water.

Question 23

Water of Crystallisation

Answer 23

Water molecules that form an essential part of the crystalline structure of a compound.

Question 24

Orbital

Answer 24

A region within an atom that can hold up to two electrons with opposite spins.

Question 25

Covalent Bond

Answer 25

A bond formed by a shared pair of electrons.

Question 26

Dative Bonding

Answer 26

Both electrons come from same atom.

Question 27

Lone Pair

Answer 27

An outer shell pair of electrons that aren’t involved in bonding.

Question 28

Electronegativity

Answer 28

Measure of the ability of an atom to attract electrons in a covalent bond.

Question 29

Ionic Bond

Answer 29

The electrostatic attraction between oppositely charged ions.

Question 30

Metallic Bond

Answer 30

The electrostatic attraction between positive ions and negative electrons.

Question 31

First Ionisation Energy

Answer 31

The energy needed to remove an electron from each atom in one mole of gaseous atoms.

Question 32

Periodicity

Answer 32

Repeating patterns across the periodic table

Question 33

One Mole of Substance

Answer 33

The amount of substance which contains as many particles as there are carbon atoms in 12g of Carbon 12

Question 34

Successive Ionisation Energy

Answer 34

The energy needed to remove each subsequent electron from each ion in 1 mole of positively charged gaseous ions.