Definitions

Question 1

Isotope

Answer 1

atom of same element with different numbers of neutrons and different masses

Question 2

relative isotopic mass

Answer 2

mass compared with 1/12th the mass of C-12

Question 3

relative atomic mass

Answer 3

weighted mean mass compared with 1/12th mass of C-12

Question 4

ionic bond

Answer 4

electrostatic attraction between positive and negative ions

Question 5

giant ionic lattice

Answer 5

from oppositely charged ions strongly attracted in all directions

Question 6

average bond enthalpy

Answer 6

measurement of strength of covalent bond, breaking of 1 mol of bonds in gaseous atoms

Question 7

electronegativity

Answer 7

ability of an atom to attract bonding electrons in a covalent bond

Question 8

periodicity

Answer 8

showing repeated trends in physical and chemical properties

Question 9

first ionic energy

Answer 9

removal of 1 mol of electrons from 1 mol of gaseous atom

Question 10

exothermic

Answer 10

releases energy: combustion

Question 11

endothermic

Answer 11

takes in energy: thermal decomposition

Question 12

enthalpy change of formation

Answer 12

formation of 1 mol of a compound from its elements

Question 13

enthalpy change of combustion

Answer 13

complete combustion of 1 mol of substance

Question 14

enthalpy change of neutralisation

Answer 14

formation of 1 mol of water from neutralisation

Question 15

lattice enthalpy

Answer 15

1 mol of ionic lattice from gaseous ions and use as a measure of the strength of ionic bonding in a giant ionic lattice

Question 16

enthalpy change of solution

Answer 16

dissolving of 1 mol of solute

Question 17

enthalpy change of hydration

Answer 17

dissolving of 1 mol of gaseous ions in water

Question 18

general formula

Answer 18

simple algebraic formula

Question 19

structural formula

Answer 19

minimal detail that shows arrangement of atoms in a molecule

Question 20

displayed formula

Answer 20

positioning of atoms and bonds between them

Question 21

skeletal formula

Answer 21

organic formula shown by removing hydrogen atoms from alkyl chains: skeleton

Question 22

homologous series

Answer 22

organic compounds that have the same functional group but each successive member is differing by CH2

Question 23

structural isomer

Answer 23

compound with same molecular formula but different structural formula

Question 24

homolytic fission

Answer 24

covalent bond breaks and one electron from bonded pair, goes to each atom forming two radicals

Question 25

hetrolytic fission

Answer 25

bonding atom recieveing both electrons from one bonding pair

Question 26

radical

Answer 26

species with an unpaired electron

Question 27

curly arrow

Answer 27

movement of electron pair, showing hetrolytic fission or formation of covalent bond

Question 28

sigma bond

Answer 28

overlap of orbitals directly between bonding atoms

Question 29

pi bond

Answer 29

sideways overlap of adjacent p-orbitals above and below the bonding C atoms

Question 30

sterioisomers

Answer 30

compounds with same structural formula with different arrangement in space

Question 31

E/Z isomerism

Answer 31

restricted rotation about a double bond

Question 32

electrophile

Answer 32

electron pair acceptor

Question 33

nucelophile

Answer 33

electron pair donor

Question 34

optical isomer

Answer 34

non-superimposable mirror image

Question 35

Standard half cell

Answer 35

The emf of a half cell compared with a hydrogen half cell at standard conditions

Question 36

Entropy

Answer 36

The disorder of a reaction (sum of products -sum of reactants