C2 Structures and Bonding Marks Foundation

M1. (i) two

or 2 1

(ii) magnesium and chloride

either order not positive / negative do not credit’chlorine’

accept Mg++ and Cl-

do not credit just Mg and Cl–

accept cation(s) and anion(s) 1

(iii) 2 1

(iv) electrons accept charges

1

(v) any three from

• (is a) giant structure/lattice structure

• crystalline / hard accept just 'crystals(s)’

• high melting point / solid

• high boiling point

• conductor (of electricity) when dissolved in water

or conductor (of electricity) when ions are free to move

• conductor (of electricity) when molten

• soluble in water 3

[7]

M2. (a) (i) small or few atoms thick or size in the range 1–100 nanometres

owtte 1

(ii) sensible idea of passing through smaller gaps owtte eg can pass through skin / pores / cells or more easily absorbed

1

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(b) any two from:

• good at absorbing UV light / radiation

• spread more easily

• cover better

• save money / use less

• transparent

• less chance of getting skin cancer or stops skin cancer

ignore more effective alone 2

(c) toxic to (cells / specific cells) allow harm / damage / kill or cause cancer

1 [5]

M3. (a) (i)

all three correct 2 marks one correct 1 mark

2

(ii) 14 1

(b) A 1

[4]

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M4. high 1

giant allow covalent

1

four 1

covalent 1

[4]

M5. (a)

all three lines correct gains 2 marks one or two correct gains 1 mark if there are more than 3 lines then lose mark for each extra line

2

(b) (i) covalent 1

(ii) four 1

(iii) hard 1

(iv) three 1

(v) soft 1

(c) carbon accept C

1 [8]

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M6. (a) CH4

4 should be below halfway up H / tail of 4 below the dotted line 1

(b) molecule 1

(c) covalent 1

[3]

M7. (a) covalent 1

(b) (i) liquid 1

(ii) fluorine accept F / F

2

do not accept fluoride 1

(c) (i) should fluoride ions be added to drinking water? 1

(ii) any one from:

• not enough reliable/valid evidence

• may be other factors involved

• it is an opinion / choice / belief / ethics issue

• it can’t be scientifically investigated allow can’t do an experiment ignore test mark independently of (c) (i)

1 [5]

M8. (a) 4 1

(b) 9 1

[2]

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M9. (a) C3H

8

capital letters for symbols numbers must be halfway or lower down the element symbol allow H

8C

3

do not allow 3:8 or C3 and H

8

1

(b) (i) electron 1

(ii) covalent 1

(c) low and small

both for 1 mark 1

[4]

M10. (a) 13 1

14 1

numbers must be in the order shown

(b) electrons have a very small mass compared to protons 1

(c) electrolysis of molten aluminium oxide 1

[4]

M11. (a) (i) element 1

(ii) compound 1

(b) an / one electron from the sodium atom 1

is lost / transferred to form a sodium ion 1

(c) (i) 8 electrons drawn on outer energy level / shell 1

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(ii) because oppositely charged ions attract each other

or

because chloride ions are negative and sodium ions are positive 1

[6]

M12. (a) because nano-sized particles are smaller than normal sized particles 1

(b) may cause harm when they are inside the body 1

[2]

M13. (a) 4 1

(b) A 1

(c) it is alkaline accept alkali / basic / base

1

(d) (i) salt 1

(ii) nitric 1

(ii) fertiliser 1

(e) because energy 1

is taken in (from the surroundings) second mark must be linked to energy

1 [8]

M14. (a) metals 1

of 8

(b) copper atoms are arranged in layers 1

copper atoms can slide over each other. 1

(c) the layers of atoms are distorted in bronze 1

[4]

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C2 Structures and Bonding Marks Foundation

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