Pearson Edexcel International GCSE in Chemistry · 4CH1 · Free · no account needed
Giant Covalent Structures — exam questions
12 original Incandio exam-style questions on Giant Covalent Structures, 26 marks, about 26 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Giant Covalent Structures — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
8 command words run through this set, and on Pearson Edexcel International GCSE Chemistry each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State (1 mark)
- one precise fact, no justification
- Give (1–2 marks)
- a short factual answer — the most common chemistry command
- Describe (2–5 marks)
- developed, linked statements of what happens or what is observed Misread as: giving one bare observation where the tariff asked for a developed account
- Explain (2–4 marks)
- the reason, in terms of particles, bonding, energy or equilibrium Misread as: describing the observation without giving the chemistry that causes it
- Suggest (1–3 marks)
- a plausible answer applying taught chemistry to an unfamiliar substance
- Identify (1–2 marks)
- the correct substance or feature selected from what is given
- Compare (2–4 marks)
- explicit comparison with a comparative word — a bare pair of statements is not a comparison
Assessed on Paper 1 (4CH1/1C) and Paper 2 (4CH1/2C), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Chemistry (4CH1) — statements 1.50 · 1.49. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 12 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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Table 1 — three forms of carbon Form Bonds per carbon atom Conducts electricity Melting point / °C diamond 4 no 3550 graphite 3 yes 3650 C60 fullerene 3 no 280 (sublimes) (a)
(1)Identify
Identify the form of carbon in Table 1 that is not a giant structure.
Table 1 — three forms of carbon Form Bonds per carbon atom Conducts electricity Melting point / °C diamond 4 no 3550 graphite 3 yes 3650 C60 fullerene 3 no 280 (sublimes) (b)
(2)Explain
Explain how the melting points in Table 1 support that choice.
Table 1 — three forms of carbon Form Bonds per carbon atom Conducts electricity Melting point / °C diamond 4 no 3550 graphite 3 yes 3650 C60 fullerene 3 no 280 (sublimes) (c)
(3)Explain
Explain, using the second column of Table 1, why graphite conducts electricity but diamond does not.
Table 1 — three forms of carbon Form Bonds per carbon atom Conducts electricity Melting point / °C diamond 4 no 3550 graphite 3 yes 3650 C60 fullerene 3 no 280 (sublimes) (d)
(3)Suggest
C60 has three bonds per carbon, like graphite, yet Table 1 shows it does not conduct. Suggest why.
Table 1 — three forms of carbon Form Bonds per carbon atom Conducts electricity Melting point / °C diamond 4 no 3550 graphite 3 yes 3650 C60 fullerene 3 no 280 (sublimes) (Total for Question 1 = 9 marks)
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(1)Which
Which element are diamond and graphite both forms of?
Element A silicon B carbon C sulfur D boron (Total for Question 2 = 1 mark)
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(1)State
State the number of covalent bonds formed by each carbon atom in diamond.
(Total for Question 3 = 1 mark)
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(1)Give
Give one use of graphite that depends on it being slippery.
(Total for Question 4 = 1 mark)
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(2)Describe
Describe the structure of graphite.
(Total for Question 5 = 2 marks)
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(3)Explain
Explain why diamond must be heated above 3500 °C before it melts.
(Total for Question 6 = 3 marks)
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(3)Explain
Explain why graphite is soft enough to write with, although its melting point is even higher than diamond's.
(Total for Question 7 = 3 marks)
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(2)Suggest
Silicon dioxide has a structure like diamond's, with every atom covalently bonded to its neighbours. Suggest why it is used to line furnaces.
(Total for Question 8 = 2 marks)
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(4)Compare
Compare the structure and bonding of diamond with those of graphite.
(Total for Question 9 = 4 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 12 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Giant Covalent Structures to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Jöns Jacob Berzelius over three rounds, marked against descriptors you can read first.
Completely free. No subscriptions, no paywalls, no account needed to start.
Back to the lesson
- Giant Covalent Structures — The same element, the same bonds — and one form cuts glass while another marks paper.
- All of Incandio Chemistry · Incandio Exam Practice