Oxford Revise AQA GCSE Combined Science Foundation | Chapter C1 answers

C1: The atom

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Answers

Extra information

Mark

AO / Specification reference

01.1

neutron – 0

proton – +1

electron – -1

1

1

1

AO1

5.1.1.4

01.2

0

1

AO2

5.1.1.4

01.3

ion

1

AO2

5.1.1.4

01.4

one mark for two inner electrons

one mark for four outer electrons

2

AO2

5.1.1.7

01.5

carbon

1

AO2

5.1.1.4

01.6

protons, neutrons

1

AO1

5.1.1.4

01.7

14 protons positive

14 neutrons neutral

14 electrons negative

1

1

AO1

5.1.1.4

02.1

filtration

1

AO2

5.1.1.2

02.2

in filter paper

1

AO2

5.1.1.2

02.3

evaporation

1

AO2

5.1.1.2

03.1

Niels Bohr – electrons orbit the nucleus at certain distances

James Chadwick – the nucleus contains neutrons

1

1

AO1

5.1.1.3

03.2

alpha particles/helium nuclei fired at gold foil

most passed through the gold foil

so most of the atom is empty space

a small number bounced back

so must have collided with something/mass/nucleus

a small number passed through but were deflected/had their direction changed

positively charged alpha particles passed near positively charged nucleus and were repelled

1

1

1

1

1

1

AO1

5.1.1.3

03.3

have no charge

03.4

Level 3: The comparisons are detailed and accurate. The writing is clear, coherent and logical and comparisons are clearly made.

5–6

AO3

5.1.1.3

Level 2: The comparisons are generally correct, although may lack detail. The writing is mainly clear, although the structure may lack logic and comparisons are not always clear

3–4

Level 1: Some comparisons are correct. The writing lacks clarity, coherence and logic, and the comparisons are not clearly expressed.

1–2

No Relevant content

0

Indicative content

  • both have electrons
  • both have positive parts
  • plum pudding model has electrons all over the place whereas nuclear model has electrons in distinct shells
  • plum pudding is positive all over whereas nuclear model has a positive centre
  • nuclear model has a nucleus whereas plum pudding model does not
  • nuclear model shows electrons within different energy levels
  • nuclear model has neutrons whereas plum pudding does not

04.1

CO2

1

AO2

5.1.1.1

04.2

hydrogen

oxygen

sulfur

1

1

1

AO2

5.1.1.1

04.3

3

1

5.1.1.1

05.1

16 × 4 = 64

63.5 + 64 = 127.5

159.5 – 127.5 = 32

1

1

1

AO2

5.1.1.5

05.2

sulfur

1

AO2

5.1.1.1

05.3

16 – 8 = 8

1

AO1

5.1.1.5

05.4

copper has multiple isotopes

relative atomic mass is an average value of the percentage of the isotopes of the element

1

1

AO1

5.1.1.6

06.1

triangle

1

AO2

5.1.1.1

06.2

A

1

AO2

5.1.1.1

06.3

C

1

AO2

5.1.1.1

5.1.1.2

06.4

D

1

AO2

5.1.1.1

5.1.1.2

06.5

NaCl or ClNa

1

AO2

5.1.1.1

07.1

lowest

innermost

two

1

1

1

AO1

5.1.1.7

07.2

sodium

1

AO2

5.1.1.7

07.3

two electrons on innermost shell

six electrons on second shell

1

1

AO2

5.1.1.7

08.1

same number of protons but a different number of neutrons

1

AO1

5.1.1.6

08.2

both have five electrons

both have five protons

boron-10 has five neutrons whereas boron-11 has six neutrons

1

1

1

AO1

5.1.1.6

08.3

\(\frac{\left( 80\times 11 \right) + \left( 20 \times 10 \right)}{100}\) \(
\begin{align}
& = \frac{880 + 200}{100}\\
& = 10.8\\
\end{align}
\)

1

1

1

AO2

5.1.1.6

09.1

filtration

1

AO1

5.1.1.2

09.2

Level 3: A full description of the method provided, with at least two pieces of equipment named.

5-6

AO1

5.1.1.2

Level 2: Basic method provided, identifying that the water needs to evaporate (either by heating or by being left). At least one piece of equipment identified.

3-4

Level 1: Method identifies idea that water needs to evaporate/be heated. No equipment named.

1-2

Level 0: No relevant content

0

Indicative content

  • mixture placed in evaporating dish
  • evaporating dish placed on beaker half-full of water
  • place beaker/evaporating dish on tripod and gauze
  • heat the mixture/water
  • using Bunsen burner
  • until crystals start to form
  • remove mixture from the heat
  • leave for the rest of the water to evaporate

09.3

chromatography

1

AO1

5.1.1.2

10.1

has atoms of two or more elements chemically bonded together

1

AO1

5.1.1.2

10.2

compound – middle image

element – top image

mixture – bottom image

one mark for one or two correct

2 marks for all correct

2

AO1

5.1.1.2

10.3

stage one – filtration

stage two – (fractional) distillation

1

1

AO2

5.1.1.2

10.4

A – beaker

B – filter paper

C – funnel

D – conical flask

1

1

1

1

AO2

5.1.1.2

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