1.	(a)	protons	mass +1	charge +  (1)
neutrons	mass +1	charge zero  (1)
electrons	mass ~ zero (or<1/1800),	charge –  (1)
nitrogen –14 has a nucleus with 7 protons and 7 neutrons  (1)
surrounded by electrons in shells (or orbitals) (or 2,5)  (1)
with configuration 1s2 2s22p3 (scores last 2 marks)  (1)	6
(b)	isotopes have the same atomic number (or same number of protons
or same element) (1)
but different number of neutrons (or mass number)  (1)	2
 
(c)	sample introduced at low pressure (or gas or vapour or vacuum) (1)
electron gun (or bombarded with electrons)  (1)
which knocks out an electron (or removes an electron)  (1)
producing a positive ion  (1)
the ions are accelerated  (1)
and focused (or made into a beam)  (1)
by an electric field (or negative plates or electric plates)  (1)
magnetic field (or magnet)  (1)
ions are deflected  (1)
deflection depends on m/z of each ion  (1)
lightest (or smallest m/z) deflected most  (1)
ions go to a detector  (1)
a small current is produced (or abundance counted)  (1)
which is fed to a computer (or recorder or display or chart etc)  (1)
electric field (or magnet) adjusted to collect ions of different mass  (1)
	Note: a picture of a spectrum can score the chart mark and the
abundance mark (if the ‘y’axis is labelled ‘abundance’ or ‘%’.	max 14
 
(d)	fraction of each component is rel. int./44  (1)
[the mark is for 44, if 42 max 1]
relative atomic mass
= 1 × 80/44 + 5 × 82/44+ 5 × 83/44 + 25 × 84/44 + 8 × 86/44  (1)
= 83.9 (1)
Krypton (1)	4
 
(e)	percentage by mass of oxygen = 38.0%  (1)
ratio of elements  = 42.9/12  :  2.4/1  :  16.7/14  :  38.0/16  (1)
                            = 3.6  :  2.4  :  1.2  :  2.4
empirical formula is  C3H2NO2  (1)
molecular formula is C6H4N2O4  (1)	4
[30]
2.	(a)	mass number = number of protons + neutrons in an atom
(or a nucleus or an isotope) (1)
(allow number of nucleons)
atomic number = number of protons in an atom (1)
example of an isotope with mass number and atomic number
and symbol or name (1)
		3
 
(b)	(i)	Ionisation (1)
with an electron gun (1) (or stream of electrons or high energy electrons)
which knocks out an electron from an atom or molecule (1)
producing a positive ion (1) (note this also scores ionisation mark)
(note M + e– ® M+ + e– + e– scores first, third and last of these marks)
 
	(Note that if ion not mentioned or negative ion used max 3 for next 9
marks, if electron CE=0)
	Acceleration (1)
with an electric field (1) (or charged plate)
 
	Deflection (1)
in a magnetic field (1) (or magnet)
depending on mass/charge (or m/z) ratio of ion (1)
particles with least m/z (or least mass) deflected most (1) (or converse)
 
	Detection (1)
Ion falls on ‘collector’ producing a current (1) (or electrically
detected or falls on a –ve plate)
fed into computer for analysis (1) (or displayed on a graph)	Max 12
 
(ii)	use mass/charge (m/z) data (1)
and relative abundance (1) (or peak height or intensity)
Ar = (abundance of isotope × mass)/sum of all abundances (1)
(can gain abundance mark here)
added together for all isotopes (1)	4
 
(c)	ionisation energy decreases down group (1)
outer electrons more shielded (1) (or further away)
	ionisation energy shows general increase across a period (1) (overall
decrease loses 3 marks)
nuclear charge increases (1) (or number of protons)
electrons in same shell (1) (or similar shielding)
 
	decrease from Mg to Al (1)
outer electron in Mg is (3)s, in Al is (3)p orbital (1) (2s or 2p loses
this mark) outer electron (or electron removed) from Al is in higher
energy level (1)
 
	decrease from P to S (1)
last electron in S is paired in a (3)p orbital (1) (2p loses mark)
repulsion between electrons in pair (1)	11
(If use Li to Ne, use same mark scheme with 2s, 2p but max 7 out of 9)
[30]

3.	Allow the following points once only for C or W or
without reference to either C or W
free / delocalised electrons / sea (not pool) of electrons (1)
	electrons move when potential difference applied / flow when voltage  (1)
applied / electrons move to +ve terminal
	(atoms) arranged in layers / lattice / crystalline
not molecules arranged in layers (1)
much energy (or heat) needed to break bonds / strong bonds
 
	allow the following points only for the appropriate element
macromolecular or giant covalent ( only for C) (1)
positive ions or cations not just metal ions (only for W) (1)
attractions between ions (not nucleus) and electrons (only for W) (1)	6
[6]

4.	From the graph:
	Mg above Na (1)
	Al similar to or above Mg (1)
	Si above Na and Mg (1)
	P lower than Mg, Al and Si (1)
	S above P, lower than Si (1)
	Ar lowest (1)	7
 
	Sodium, magnesium and Al metallic (1)
Strength of metal-metal bonds increases from Na to Al (1)
More protons (or bigger charge on ion or more delocalised electrons) (1)
Ions attract delocalised electrons more strongly (1)	4
 
	Silicon has covalent bonds (1)
Macromolecule (1)
Many strong bonds to be broken (1)	3
	S8 (1)
P4 (1)
C12 (1)
weak intermolecular forces (1)
van derWaals’ (1)
Stronger between larger molecules (1)	6
	Argon consists of free atoms with weak van der Waals’ forces between atoms (1)	1
[21]

5.	(a)	
	from diag (cubic (1) ions (or Na, Cl or +,–) placed correctly (1)
(minimum of 4 species)
from diag or stated (ionic (1) lattice (1)
high mpt (1) due to strong ionic bonds (1)
conducts when molten (or in solution) (1) mobile ions (1)
[OR non conductor when solid (1) no mobile ions (or electrons) (1)]	8

from diag (3 hexagons in any one layer (1) planes (1))
stated or from diag: macromolecular (1)
must be stated: covalent (1)
high mpt (1) due to strong covalent bonds (1) 
conducts when solid (1) delocalised electrons (1)
Note if free not delocalised mentioned penalise
once only: for quality of language
		8
	
from diagram: spheres close together (1)
	stated or from diagram (hexagonal in one plane or lattice (1)
ions (1) delocalised electrons (1)
high mpt (1) strong metallic bonds (1)
conducts (1) delocalised electrons (1)	8
		Max 23
 
(b)	electron pairs repel as far apart as possible (1)
lone pairs repel more (1)

Note if angles not drawn on diagram penalise once only
		7
[30]
6.	general increase across period (1)
can score this and points 4, 7 on graph
	because number of protons (or nuclear charge) increases (1)
	but electrons in same shell (or similar shielding) (1)
	fall from Mg to Al (1)
	Al’s outer electron is in a p orbital (1)
	higher in energy than s electron in Mg (1)
if wrong period –1
	fall from P to S (1)
	two of the p electrons in S are paired  (or in same orbital) (1)
[9]

7.	(a)	Ionic  (1)
lattice  (1)
e.g. NaCl  (1)
conducts when molten  (1)
due to mobile ions  (1)
     sketch scores (2)  { 4 ions placed correctly in a square  (1)
	{ extended to 3 dimensions  (1)	max 6
 
	macromolecular  (1)
covalent  (1)
e.g.  diamond (or graphite)  (1)
conductor (or conducts when solid) (1)
electrons localised in covalent bonds (or delocalised electrons in rings) (1)
diamond	graphite
tetrahedral round a C  (1)	2 ‘fused’ hexagons  (1)
extended from other Cs  (1)	2 layers (planes)  (1)
 
    sketch scores  (2)	max 6
molecular  (1)
or molecules
 
	covalent  (1)
e.g. iodine  (1) etc
	weak (van der Waals) forces between molecules  (1)
non conductor  (1)
electrons localised  (1)
    sketch scores  (1)
regular array of molecules
	example of a metal (eg Mg)  (1)
metallic bonding (or stated to be a metal)  (1)
positive ions (or atoms)  (1)
surrounded by delocalised electrons  (1)
conducts when solid  (1)
due to delocalised electrons  (1)
	
	Note if candidate deals with two crystals of the same type
eg diamond & graphite, award max 3 for worst of the two answers	max 6
 
(b)	5 electron pairs  (1)
including one lone pair  (1)
repel as far apart as possible  (1)
lone pair – bond pair repulsion > bp – bp  (1)
pushes S–F bonds closer together  (1)
shape is 
 
	angles <90  (1) and <120  (1)     or (<90  (1) and 120  (1))
           (85 – 89)     (115 – 119)       (85 – 89)      (115 – 120)
N.B. if not 5 pairs  of electrons can score only 3rd & 4th marks	max 8
 
(c)	small cation (or large charge to size ratio)  (1)
anion is distorted  (1)
covalent character  (1)
e.g. LiI  (1)
or LiBr, any Be compound except BeF2
AlCl3, AlO3, MCl3, Li2CO3	max 4
[30]

8.	(a)	Proton: mass 1, charge + 1 (1)
Neutron: mass 1, charge 0 (1)
Electron 1/1840, charge -1 (1)
Allow mass = 0, or negligible, or 1/1800 to 1/2000
	Isotopes have the same number of protons (1)
OR atomic number
	different number of neutrons (1)
	Isotopes have the same electronic configuration (1)
OR same number of electrons
	Chemical properties depend on electrons	7
 
(b)	 ×12 (1)
OR  × 12 or in words
	Spectrum gives (relative) abundance (1)
OR % or amount
 
	And m/z (1)
Multiply m/z by relative abundance for each isotope (1)
Allow instead of m/z mass no, Ar or actual value from example
	Sum these values (1)
Divide by the sum of the relative abundances (1)
only award this mark if previous 2 given
Max 2 if e.g. has only 2 isotopes	7
[14]

9.	(a)	Elements in the p block have their outer electron(s) in
p orbital(s) or levels or sub-shells (1)
example of element (1)
correct electronic configuration (1)	3
 
(b)	Pattern in the change in the properties of a row of elements (1)
OR Trend in the properties of elements across period
	Repeated in the next row (1)
OR element underneath (or in same group) has similar properties
 
	atomic radius
decreases across the row (1)
CE if trend is wrong
	number of protons increases (1) (or nuclear charge increases)
more attraction for electrons in the same shell (1)
 
	electronegativity
increases across the row (1)
number of protons increases (1) (or nuclear charge)
atomic radius decreases (1) (or shielding remains the same or electrons
in the same shell) more attraction for bonding or shared electrons (1)
 
	conductivity
decreases row (1)
OR significant drop from Al to Si
	Na–Al metals (1)
OR metallic bonding or description of metallic bonding
	Two of Si - Ar non metals (1)
OR molecular or covalent
	EITHER electrons free to move (delocalised) in metals
OR electrons unable to move in non-metals (1)	13
[16]

10.	(a)	Ionisation (1)
High speed or high energy electrons or electron gun (1)
NOT bombard
NOT beam or stream of electrons
	Knocks out (outer) electron (1)
	Forming positive ion - could be from Ti ® Ti+ + e– (1)
Accept + ion later in question to clarify charge of ion
Ti + e– ® Ti+ + 2 e– worth 2 marks
Ignore state symbols
 
	Acceleration (1)
	By electric field or attraction to negative plate or electrostatic attraction (1)
NOT repelled by + plate
Allow passed through positive & negative plates / oppositely
charged plates
Not just charged plates
	Deflection (1)
	By magnetic field or magnet or electromagnet (1)
	Detection (1)
	Idea that ions collected at detector and generate current (1)
	Both ions have the same m / z value (of 24) or valid arguments
in terms of the doubled charge on 48Ti2+ exactly counteracting its
doubled mass (1)
	Deflected equally (so detected together) or deflection dependent
on m / z value (1)
Can’t get this from previous section
		10
 
(b)	Differ in mass number or number of neutrons (1)
Same proton / atomic number (1)
Ignore reference to electrons here
	Isotopes have the same chemical properties (1)
	because all have the same electron configuration or number of electrons
or same number of valence electrons (so no chemical difference) (1)
This mark is tied to the above mark or near miss [similar etc] in M3
		4
 
(c)	Mean mass of an atom or (isotope) (1) [NOT mass of average atom]
	Relative to 1/12 mass of 12C atom atc. Or to 12C taken as 12.000 or
exactly 12 (1)
Isotope can be accepted
OR  (1) × 12 (1)
OR  (1) × 12 (1)
	Ar = (46 × .0802) + (47 × .0731) + (48 × .7381) + (49 × .0554) + (50 × .0532) (1)
	= 47.93 answer to 2 d.p (1)
47.92 is acceptable
Must be 5 sets of values
Ignore transcription errors BUT DON’T ignore missing 100 C.E.
If missing isotope C.E.
		4
[18]

11.	(a)	SF6 shown as octahedral / square based bipyramid (1)
Bond angle: 90° or 180° and 90° (1)
Shape = octahedral (1)
If lone pair shown then C.E.= 0 / 4

Wrong symbols - no diagram mark
	Equal repulsion between 6 bonding or shared electron pairs QoL (1)
 
	AlCl4– shape shown as tetrahedral (1)
Bond angle = 109° to 109.5° (1)
Shape = tetrahedral (1)
If lone pair shown then C.E = 0/4

(Equal repulsion between) 4 bonding pairs or shared electron pairs (1)
QoL may be awarded here also
Mark all points independently
		8
 (b)	Solvent has low bp or weak intermolecular forces or evaporates quickly (1)
	(Solvent) needs energy to evaporate (to overcome intermolecular forces)
or valid reference to latent heat of vaporisation (or evaporation is
endothermic) (1)
OR higher energy or faster molecules more likely escape
so mean energy (and hence temperature) falls
	Energy taken from the skin (and so it cools) (1)
	Fragrance or perfume (molecule) slowly spreads (through the room) (1)
	By random movement or diffusion (of the perfume / fragrance) (1)	4
[12]

12.	(a)	Macromolecular or giant structure (1)	7
Accept diamond shaped lattice
Intermolecular forces / molecular lattice / comparison to graphite structure, = ‘con’
	Held together by covalent bonds (1)
‘Giant covalent structure’ earns both M1 and M2
	(Much) energy needed to break bonds         Or many bonds to be broken (1)
Mark tied to earning ‘covalent’ M2       If explanation is clearly of ionic bonding = CE
	Vand der Waal / temporary induced dipole-dipole / London / disperse forces (1)
	Forces increase with size or with number of electrons or with surface area etc. (1)
Description must be of the molecules of P and S
	P4 or Mr = 124 (1)	S8 or Mr = 256 (1)
If M6 (i.e. P4) and M7 (i.e. S8) are not attempted, allow S molecule bigger /more surface area than P molecule for 1 mark
 
(b)	Diagram NaCl = cubic (1)
Allow if 3 full faces shown correctly

	Ions identified and placed properly (1)
If diagram shows ‘+’ and ‘–’ signs rather than symbols for ions, identification of the ions could be from the text
	(Bonding) identified in writing as being ionic (1)
Not ionic molecule
	Due to strong electrostatic attractions or similar description
about attraction between oppositely charged ions.(1)   QoL	4
Not just: ‘ionic bonds are strong’ / ‘need much energy to break bonding’
 (c)	Be – no reaction with water or steam (1)	4
Not: Be does not dissolve
Mg reacts with steam                            or reacts slowly with cold/hot water (1)
White solid (not precipitate) formed        Bubbles (1)
or Mg glows or burns (with bright white light)	Not ‘fizzes’ or ‘gas evolved’
Mg + H2O ® MgO + H2	Mg + 2H2O ® Mg(OH)2 + H2 (1)
Condition, equation and observation marks are tied. Candidate can’t mix-and-match but, when both conditions quoted, select the higher scoring option
[15]

13.	(a)	Hydrogen bonding (full name)	1
Diagram shows at least one δ+H and at least one δ–F	1
(If full charges shown, M2 = 0)
	3 lone pairs shown on at least one fluorine atom	1
H-bond indicated, between H and a lone pair on F

(If atoms not identified, zero for diag)
(‘Fl’ for fluorine - mark to Max 2)
(Max 1 if only one HF molecule shown, or HCl shown)
	Dipole results from electronegativity difference or values quoted	1
(‘difference’ may be inferred)
(Allow explanation – e.g. F attracts bonding electrons more strongly than H)
	QoL	Fluorine more/very electronegative or iodine less electronegative	1
or electronegativity difference too small in HI
Comparison required, may be implied.
	HI dipole weaker or bonding e– more equally shared  -  wtte	1

(b)	NaCl is ionic (lattice)	1
(Treat atoms/molecules as a contradiction)
(Accept ‘cubic lattice’)
	Diamond is macromolecular/giant covalent/giant atomic/giant molecular	1
(NOT molecular or tetrahedral)
(Ionic/van der Waals’ = CE = 0)
	(Many) covalent/C-C bonds need to be broken / overcome	1
(NOT just ‘weakened’ etc.)
(‘Covalent’ may be inferred from diagram)
(Treat diagram of graphite (without one of diamond) as a
contradiction – lose M2 but allow M3/M4])	1
	Which takes much energy or covalent bonds are strong	1
(References to van Der Waals’ bonds breaking lose M3/M4)
[11]

14.	QoL	Bonding	Both covalent	(linked statement)	1
	Structure	Iodine  = molecular /I2 (stated or in diagram)	1
[treat incorrect diagram as contradiction]
	Diamond = giant molecular/macromolecular/giant	1
	covalent / giant atomic (stated only)
Reference to van der Waals’ /dipole-dipole = contradiction
	QoL	Iodine	Weak van der Waals’ forces / induced dipole-induced	1
	dipole
	Diamond	Covalent bonds would need to be broken	1
	Many / strong covalent bonds OR much energy needed	1
	Tied to M5	or near miss
[If ionic/metallic structure suggested then CE for that substance] [If hydrogen bonding suggested, for I2 lose M2 & M4; for diamond lose M3,M5&M6]
[6]

15.	Structure and hardness
	M1	Q of L	both macromolecular/giant atomic/giant covalent/giant molecular;	1
M2	C atoms in diamond joined to 4 other C atoms / diagram with min 5 C
atoms i.e. shows tetrahedral shape / coordination number = 4;	1
M3	C atoms in graphite joined to 3 other C atoms diagram with clear
extended hexagonal plane/pattern i.e. shows trigonal planar shape /
coordination number = 3;	1
M4	diamond hard / crystal strong;	1
(not diamond stronger than graphite)
M5	because of 3-D structure / rigid structure / not layered;	1
M6	graphite (soft) as layer can slide over each other;	1
M7	Q of L	as only (weak) van der Waals’ forces between layers;	1
 
Melting point (for either allotrope)
M8	covalent bonds must be broken / overcome;	1
M9	which are strong / many / hard to break;	1
(M9 tied to M8)
	Other difference
M10	diamond is non-conductor of electricity, graphite is conductor	1
OR appropriate difference in appearance;
[9]
16.	
[5]

17.	(i)	
	2
	(1)	(1)
[Do not allow shapes which show a lone pair]
	BF3	Trigonal planar/planar triangular	1
[Not plane triangle]
	BF	Tetrahedral	1
[Not distorted tetrahedral]
	Equal repulsion between (4) bonding pairs/bonds/bonding electrons	1
109(½) °	1
 
(ii)	Lone pair donated / both electrons supplied by one atom	1
from F– (to B)	1
[ignore missing charge or fluorine or ‘atom’]
	dative/dative covalent/coordinate bonding	1
[9]
18.	(a)	heated / vaporised / boiled
	passed into column / tower
	condense at different heights / liquefy at different heights
	similar molecules (size, bp, mass) condense together /  (1) 
small molecules at the top and big molecules at the bottom	4

(b)	larger  (1)
	reduces decomposition  (1)	2
 
(c)	(i)	hexane or valid isomers  (1)
propene  (1)	2
(ii)	atom / molecule / species with odd / unpaired / single electron  (1)	1
(iii)	C6H13. / C3H7. (penalise missing . once in question 8)  (1)	1
(iv)	C3H6  (1)	1
 
(d)	CHCl3  (1)
C2HBrClF3 or correct structural formula  (1)
	2
[13]
19.	(a)	pollutants: CO (1)
NO or NO2 (1)
unburned hydrocarbons (1)
	CO from incomplete combustion (1)
eg C8H18 + 8 ½ O2 ® 8CO + 9H2O	(eqn 1)
NO from N2 + O2 ® 2NO (1)
	spark (1)		max 7
	removal: reaction between NOx and CO or CxHy
	to form harmless products (1)
	eqn : 2NO + 2CO ® N2 + 2CO2 (2)
	C8H18 + 25NO ® 8CO2 + 9H2O + 12½N2 (2)
one of Pt/Rh/Pd catalyst (1)	max 4
 
(b)	Demand for heavy fraction: low or for petrol: high (1)
Supply of heavy fraction: high or of petrol: low (1)
larger Mr are less volatile/have higher bp (1)
due to stronger intermolecular forces (1)	4
[15]

20.	Cracking (1)
	radical mechanism (1)
	Any two equations e.g 	C10 H22 ® C2H4 + C8H18
		C10H22 ® 2C2H4 + C6H14 (2)
 
	C10H22 or larger alkanes: 	low demand/high abundance/less useful (1)
	C2H4 or smaller alkanes: 	high demand/low abundance/more useful (1)
	Uses: ethene to make polymers/plastics/ethanol (1)
	octane or smaller alkanes  - for petrol or fuels (1)	8
[8]

21.	(a)	Missing fraction = naphtha (allow naphtha from list if not quoted
separately) (1) Order = mineral oil (lubricating oil), gas oil (diesel),
	kerosene (paraffin),
          naphtha, petrol (gasoline) (1)
Mark order consequential on M1 (if no missing fraction
given, M2 = 0) Accept correct reversed order
	Negative temperature gradient on the column
or temperature of column decreases upwards (1)
	Larger molecules or heavier fractions condense at higher temperatures or
lower down the column or reference to different boiling points
(ignore mp) (1)	4
 
(b)	Type of mechanism = (free) radical / homolytic fission - used in complete
sentence phrase (1)
	C21H44 ® 3 C2H4 + 2 C3H6 + C9H20 correct alkenes (1)
	Accept CH2CH2 & CH2CHCH3 all correct (1)	3
 
(c)	(i)	Sulphur (containing impurities) burn to form or forms SO2 or correct
oxides of sulphur (if oxide identified, must be correct) (1)
OR equation: e.g. S + O2 ® SO2 or H2S + 1½O2 ® SO2 + H2O
	Leading to acid rain (must have specified oxides of S or burning)
or toxic product or respiratory problems (1)
 
(ii)	NO formed by reaction between N2 and O2 from the air (1)
OR N2 +O2 ® 2NO
High combustion temperature or spark in engine (1)
provides EA or sufficient heat / energy to break NºN (1)
 
(iii)	Need to remove NO as forms acid rain or toxic product or causes
respiratory problems (1)
2NO + O2 ® 2NO2 (1)
4NO2 + O2 + 2H2O ® 4HNO3 (1)
	Need to remove CO as it is poisonous (1)
	Catalytic converter (1)
uses Pt / Rh / Pd / Ir (wrong answer cancels a correct one) (1)
Provides active sites / reduces EA (1)
Forms N2 + CO2 (1)
2NO + 2CO ® N2 + 2CO2 (correct equation worth last 2 marks)
(1)	Max 10
[17]