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C1 ATOMIC STRUCTURE ANDPERIODIC TABLEQuestion Practice
Name: ________________________
Class: ________________________
Date: ________________________
Time: 185 minutes
Marks: 179 marks
Comments: HIGHER TIER
Page 1 of 57
This question is about calcium.
(a) What type of compound is calcium oxide?
Tick one box.
An acid
A base
A carbonate
A salt
(1)
1
(b) Ionic compounds, such as calcium oxide, have high melting points.
Complete the sentences. Use words from the box.
bonds forces ions layers
Calcium oxide has a giant ionic lattice in which there are strong electrostatic
______________________ of attraction in all directions.
(1)
Page 2 of 57
(c) The figure below shows the electronic structure of an oxygen atom and a calcium atom.
Describe how the calcium atom and the oxygen atom forms calcium oxide.
You should give the charge on each ion formed.
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(4)
(Total 6 marks)
Page 3 of 57
Figure 1 shows a reactor used to produce titanium from titanium(IV) chloride.
Figure 1
The chemical equation for the reaction of titanium(IV) chloride with sodium is:
TiCl4 + 4Na Ti + 4NaCl
titanium(IV) chloride + sodium titanium + sodium chloride
(a) For one reaction:
• 1615 kg titanium(IV) chloride reacted completely with 782 kg sodium• 1989 kg sodium chloride was produced.
Calculate the mass of titanium produced from this reaction.
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Mass of titanium = _________________ kg
(1)
2
Page 4 of 57
(b) The table below shows the solubility of sodium chloride in 100 cm3 of aqueous solution atdifferent temperatures.
Solubility of sodium chloride in g per100cm3
Temperature in °C
35.72 10
35.89 20
36.09 30
37.37 40
36.69 50
37.04 60
On Figure 2:
• plot this data on the grid• draw a line of best fit.
Figure 2
(3)
Page 5 of 57
(c) The product sodium chloride is dissolved in water to separate it from titanium.
At 30 °C the solubility of sodium chloride is 36 kg per 100 dm3.
Calculate the minimum volume of water in dm3, at 30 °C, needed to dissolve 1989 kgsodium chloride.
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Volume of water = ____________________ dm3
(2)
(d) Calculate the percentage by mass of titanium in titanium(IV) chloride (TiCl4).
Give your answer to 3 significant figures.
Relative atomic masses (Ar): Cl = 35.5; Ti = 48
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Percentage of titanium by mass = _______________ %
(3)
(e) Suggest why the reaction is done in an atmosphere of dry argon instead of air containingwater vapour.
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(3)
Page 6 of 57
(f) Explain why titanium conducts electricity.
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(3)
(Total 15 marks)
Page 7 of 57
A student used paper chromatography to identify the pigments in spinach leaves.
She used propanone as a solvent.
Figure 1 shows the student’s results.
Figure 1
(a) Name the mobile phase and the stationary phase in the student’s experiment.
Mobile phase ________________________________________________________
Stationary phase _____________________________________________________
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(2)
3
Page 8 of 57
(b) What does Figure 1 tell you about the green pigment from spinach?
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(3)
(c) Write the equation that links distance moved by solvent, distance moved by solute and Rf
value.
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(1)
(d) Use Figure 1 to calculate the Rf value for pigment B.
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Rf value = ________________
(3)
Page 9 of 57
(e) Another student set up the apparatus shown in Figure 2.
Figure 2
This student did not set up the apparatus correctly.
Identify the errors the student made.
Explain how the errors she made would affect her results.
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(4)
(Total 13 marks)
Page 10 of 57
This question is about magnesium.
(a) (i) The electronic structure of a magnesium atom is shown below.
Use the correct answer from the box to complete each sentence.
electrons neutrons protons shells
The nucleus contains protons and _________
The particles with the smallest relative mass that move around the nucleus are called
_________
Atoms of magnesium are neutral because they contain the same number of
electrons and _________
(3)
4
(ii) A magnesium atom reacts to produce a magnesium ion.
Which diagram shows a magnesium ion?
Tick ( ) one box.
(1)
Page 11 of 57
(b) Magnesium and dilute hydrochloric acid react to produce magnesium chloride solution andhydrogen.
Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)
(i) State two observations that could be made during the reaction.
1. ____________________________________________________________
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2. ____________________________________________________________
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(2)
(ii) In this question you will be assessed on using good English, organisinginformation clearly and using specialist terms where appropriate.
Describe a method for making pure crystals of magnesium chloride from magnesiumand dilute hydrochloric acid.
In your method you should name the apparatus you will use.
You do not need to mention safety.
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(6)
(Total 12 marks)
Page 12 of 57
This question is about atomic structure and elements.
(a) Complete the sentences.
(i) The atomic number of an atom is the number of _______________________
(1)
(ii) The mass number of an atom is the number of ________________________
______________________________________________________________
(1)
5
(b) Explain why an atom has no overall charge.
Use the relative electrical charges of sub-atomic particles in your explanation.
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(2)
(c) Explain why fluorine and chlorine are in the same group of the periodic table.
Give the electronic structures of fluorine and chlorine in your explanation.
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(2)
Page 13 of 57
(d) The diagram shows the electronic structure of an atom of a non-metal.
What is the chemical symbol of this non-metal?
Tick ( ) one box.
Ar
O
S
Si
(1)
(e) When elements react, their atoms join with other atoms to form compounds.
Complete the sentences.
(i) Compounds formed when non-metals react with metals consist of
particles called _________________________ .
(1)
(ii) Compounds formed from only non-metals consist of
particles called ____________________ .
(1)
(Total 9 marks)
Page 14 of 57
This question is about atoms and isotopes.
(a) Atoms contain protons, neutrons and electrons.
A lithium atom has the symbol
Explain, in terms of sub-atomic particles, why the mass number of this lithium atom is 7.
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(3)
6
(b) Amounts of substances can be described in different ways.
Complete the sentences.
One mole of a substance is the relative formula mass in
___________________________________________________________________
The relative atomic mass of an element compares the mass of an atom of an element withthe mass of an atom of
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(2)
(c) Two isotopes of oxygen are and
Describe the similarities and differences between the isotopes and
You should refer to the numbers of sub-atomic particles in each isotope.
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(3)
(Total 8 marks)
Page 15 of 57
In 1866 John Newlands produced an early version of the periodic table.
Part of Newlands’ periodic table is shown below.
Column 1 2 3 4 5 6 7
H Li Be B C N O
F Na Mg Al Si P S
Cl K Ca Cr Ti Mn Fe
Newlands’ periodic table arranged all the known elements into columns in order of their atomicweight.
Newlands was trying to show a pattern by putting the elements into columns.
(a) Iron (Fe) does not fit the pattern in column 7.
Give a reason why.
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(1)
7
(b) In 1869 Dmitri Mendeleev produced his version of the periodic table.
Why did Mendeleev leave gaps for undiscovered elements in his periodic table?
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(1)
(c) Newlands and Mendeleev placed the elements in order of atomic weight.
Complete the sentence.
The modern periodic table places the elements in order of
______________________ .
(1)
Page 16 of 57
(d) Lithium, sodium and potassium are all in Group 1 of the modern periodic table.
Explain why.
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(2)
(Total 5 marks)
This question is about the halogens (Group 7).
(a) How do the boiling points of the halogens change down the group from fluorine to iodine?
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(1)
8
(b) Sodium bromide is produced by reacting sodium with bromine.
Sodium bromide is an ionic compound.
(i) Write down the symbols of the two ions in sodium bromide.
______________________________________________________________
(1)
(ii) Chlorine reacts with sodium bromide solution to produce bromine and one otherproduct.
Complete the word equation for the reaction.
chlorine + sodium bromide bromine + ______________
(1)
(iii) Why does chlorine displace bromine from sodium bromide?
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(1)
(iv) Use the Chemistry Data Sheet to help you to answer this question.
Suggest which halogen could react with sodium chloride solution to produce chlorine.
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(1)
(Total 5 marks)
Page 17 of 57
The positions of eight elements in the modern periodic table are shown below.
9
Choose the correct chemical symbols to complete each sentence.
(a) The two metals that react vigorously with water are ____________ and
____________ .
(1)
(b) The element used as a catalyst in the Haber process is ____________ .
(1)
(c) The two elements with five electrons in their outer shell (highest energy
level) are ____________ and ____________ .
(1)
(d) Iron has ions with different charges.
The other metal that has ions with different charges is ____________ .
(1)
(Total 4 marks)
Page 18 of 57
Elements are made up of atoms.
(a) What is the approximate radius of an atom?
Tick one box.
1 × 10 m
1 × 10−1 m
1 × 10−10 m
1 × 10−100 m
(1)
10
(b) The figure below shows the atoms of five elements.
The letters are not the symbols of these elements.
Complete the sentence.
All of the elements in the figure above are in Group
_____________ of the periodic table.
(1)
(c) Which two atoms in the figure above are isotopes of the same element?
Explain your answer fully.
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(3)
Page 19 of 57
(d) The halogens are in Group 7 of the periodic table.
Explain the trend in reactivity of the halogens.
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(6)
(Total 11 marks)
The figure below shows a simple model of the three states of matter.
(a) What is the correct equation to work out the density of a material?
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(1)
11
(b) A student explains density to his teacher using the particle model in the figure above.
His teacher says there are limitations to the model.
Give two limitations of the particle model in the figure above.
1. _________________________________________________________________
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2. _________________________________________________________________
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(2)
Page 20 of 57
(c) When the gas in a container with a fixed volume is heated, the pressure increases as thetemperature increases.
Explain why the pressure increases.
Use the model in the figure above to help you.
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(4)
(Total 7 marks)
Page 21 of 57
Figure 1 shows the plum pudding model of the atom.
This model was used by some scientists after the discovery of electrons in 1897.
Figure 1
Plum-pudding model
In 1911 the scientists Geiger and Marsden investigated the effect of firing alpha particles at verythin sheets of gold foil.
Their experiment is shown in Figure 2. The arrows show the paths taken by alpha particles in theexperiment.
Figure 2
(a) Explain why scientists replaced the plum pudding model of the atom with the nuclear modelof the atom as a result of the experiment.
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(4)
12
Page 22 of 57
(b) According to modern measurements:
• the radius of an atom is about 1 × 10 –10m
• the radius of an atomic nucleus is about 1 × 10 –14m
Show that these values fit with the nuclear model of the atom.
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(2)
(c) In 1931 a scientist discovered that there are hydrogen atoms with mass number 2 as wellas hydrogen atoms with mass number 1.
A year later, another scientist discovered neutrons.
Explain why the discovery of neutrons could explain the presence of hydrogen atoms withdifferent mass numbers.
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(3)
(d) How would the results of the experiment shown in Figure 2 change if neutrons were usedinstead of alpha particles to bombard a thin sheet of gold?
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(2)
(Total 11 marks)
Page 23 of 57
In 1869 there were 60 known elements.
Mendeleev arranged the elements in order of their atomic mass (atomic weight).
He realised that elements with similar properties occurred at regular intervals.
(a) Suggest why one of the groups that is on today’s periodic table was not in Mendeleev’speriodic system.
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(1)
13
(b) Explain the arrangement of the first 20 elements in today’s periodic table.
You should answer in terms of atomic structure.
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(2)
Page 24 of 57
(c) A student put some potassium bromide solution in a test tube.
She added a few drops of chlorine solution and observed the result.
She repeated the process using different potassium halide salts and different halogens.
The table below shows the student’s results.
Solution ofhalogen
Potassiumchloride solution
Potassiumbromide solution
Potassium iodidesolution
Chlorine Orange colour
formsBrown colour
forms
Bromine No reaction Brown colour
forms
Iodine No reaction No reaction
Give the order of reactivity of the halogens from the results in the table above.
Explain how you used the results to show this order of reactivity.
Order ______________________________________________________
Explanation _______________________________________________________
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(2)
(d) Write a balanced ionic equation for the reaction of chlorine with bromide ions in solution.
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(3)
Page 25 of 57
(e) Explain the order of reactivity of Group 7 elements.
Include information about atomic structure.
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(2)
(Total 10 marks)
The elements in Group 1 of the periodic table are metals.
(a) The elements in Group 1 are called the alkali metals.
Why are they called the alkali metals?
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(2)
14
(b) Explain the increase in reactivity of elements further down the group.
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(4)
Page 26 of 57
(c) Lithium oxide is an ionic compound.
Draw a dot and cross diagram to show how lithium and oxygen combine to form lithiumoxide.
Only show the electrons in the outer shell of each atom.
Give the charges on the ions formed.
(4)
(Total 10 marks)
Sulfur is a non-metal.
Sulfur burns in the air to produce sulfur dioxide, SO2
(a) Why is it important that sulfur dioxide is not released into the atmosphere?
Tick (✔) one box.
Sulfur dioxide causes acid rain.
Sulfur dioxide causes global dimming.
Sulfur dioxide causes global warming.
(1)
15
(b) Sulfur dioxide dissolves in water.
What colour is universal indicator in a solution of sulfur dioxide?Give a reason for your answer.
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(2)
Page 27 of 57
(c) Sulfur dioxide is a gas at room temperature.
The bonding in sulfur dioxide is covalent.
Explain, in terms of its structure and bonding, why sulfur dioxide has a low boiling point.
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(3)
(d) In this question you will be assessed on using good English, organising information clearlyand using specialist terms where appropriate.
Sulfur dioxide is produced when fossil fuels are burned.
It is important that sulfur dioxide is not released into the atmosphere.
Three of the methods used to remove sulfur dioxide from gases produced when fossil fuelsare burned are:
• wet gas desulfurisation ( W)
• dry gas desulfurisation ( D)
• seawater gas desulfurisation ( S).
Information about the three methods is given in the bar chart and in Table 1 and Table 2.
Method of removing sulfur dioxide
Page 28 of 57
Table 1
Method Material used How material is obtained
W Calcium carbonate, CaCO3 Quarrying
DCalcium oxide, CaO Thermal decomposition of calcium
carbonate:
CaCO3 CaO + CO2
S Seawater From the sea
Table 2
Method What is done with waste material
WSolid waste is sold for use in buildings.Carbon dioxide is released into the atmosphere.
D Solid waste is sent to landfill.
S Liquid waste is returned to the sea.
Page 29 of 57
Evaluate the three methods of removing sulfur dioxide from waste gases.
Compare the three methods and give a justified conclusion.
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(6)
(Total 12 marks)
Page 30 of 57
Use the periodic table and the information in the table below to help you to answer the questions.
The table shows part of an early version of the periodic table.
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7
H
Li Be B C N O F
Na Mg Al Si P S Cl
(a) Hydrogen was placed at the top of Group 1 in the early version of the periodic table.
The modern periodic table does not show hydrogen in Group 1.
(i) State one similarity between hydrogen and the elements in Group 1.
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(1)
16
(ii) State one difference between hydrogen and the elements in Group 1.
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(1)
(b) Fluorine, chlorine, bromine and iodine are in Group 7, the halogens.
The reactivity of the halogens decreases down the group.
Bromine reacts with a solution of potassium iodide to produce iodine.
Br2 + 2KI 2KBr + I2
(i) In the reaction between bromine and potassium iodide, there is a reduction ofbromine to bromide ions.
In terms of electrons, what is meant by reduction?
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(1)
(ii) Complete the half equation for the oxidation of iodide ions to iodine molecules.
2I−
(2)
Page 31 of 57
(iii) Explain, in terms of electronic structure, why fluorine is the most reactive element inGroup 7.
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(3)
(Total 8 marks)
Glass is made from silicon dioxide.
© Velirina/iStock/Thinkstock
(a) Silicon dioxide has a very high melting point.
Other substances are added to silicon dioxide to make glass. Glass melts at a lowertemperature than silicon dioxide.
Suggest why.
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(1)
17
Page 32 of 57
(b) Sodium oxide is one of the substances added to silicon dioxide to make glass.
(i) Sodium oxide contains Na+ ions and O2– ions.
Give the formula of sodium oxide.
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(1)
(ii) Sodium oxide is made by heating sodium metal in oxygen gas.
Complete the diagram to show the outer electrons in an oxygen molecule (O2).
(2)
(c) Glass can be coloured using tiny particles of gold. Gold is a metal.
Describe the structure of a metal.
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(3)
(Total 7 marks)
Page 33 of 57
Kelp is a seaweed.
Kelp can be used in foods and as a renewable energy source.
© Ethan Daniels/Shutterstock
(a) Scientific experiments, on their own, cannot fully answer one of the following questions.Which one?
Tick ( ) one box.
Questions Tick (✔✔✔✔)
How much carbon dioxide is produced when 100 g of kelp is burned?
Does kelp give out more heat energy than coal?
Will kelp last longer than coal as an energy source?
Which fuel, kelp or coal, produces the most ash when burned?
(1)
18
(b) Scientists cannot answer the question ‘should people use kelp instead of coal as an energysource?’
Give two reasons why.
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(2)
Page 34 of 57
(c) Sodium iodide can be produced from kelp.
(1)
(i) How many electrons are in the outer shell of an iodine atom?
(ii) Sodium iodide contains sodium ions (Na+) and iodide ions (I–).
Describe, as fully as you can, what happens when sodium atoms react with iodineatoms to produce sodium iodide.
You may use a diagram in your answer
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(3)
Page 35 of 57
(iii) The diagram shows the structure of sodium iodide.
Solid sodium iodide does not conduct electricity.
Why does sodium iodide solution conduct electricity?
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(1)
(iv) When sodium iodide solution is electrolysed, iodine is formed at the positiveelectrode.
Complete and balance the half equation for the formation of iodine.
_____I− → I2 + _____e−
(1)
(v) What is formed at the negative electrode when sodium iodide solution is electrolysed?
Explain why.
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(2)
(Total 11 marks)
Page 36 of 57
The picture shows a copper kettle being heated on a camping stove.
Copper is a good material for making a kettle because:
• it has a high melting point
• it is a very good conductor of heat.
(a) Explain why copper, like many other metals, has a high melting point.
Your answer should describe the structure and bonding of a metal.
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(4)
19
Page 37 of 57
(b) Aeroplanes contain many miles of electrical wiring made from copper. This adds to themass of the aeroplane.
It has been suggested that the electrical wiring made from copper could be replaced bycarbon nanotubes which are less dense than copper.
The diagram shows the structure of a carbon nanotube.
(i) What does the term ‘nano’ tell you about the carbon nanotubes?
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(1)
(ii) Like graphite, each carbon atom in the carbon nanotube is joined to three othercarbon atoms.
Explain why the carbon nanotube can conduct electricity.
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(2)
(Total 7 marks)
Page 38 of 57
(a) Dmitri Mendeleev was one of the first chemists to classify the elements by arranging themin order of their atomic weights. His periodic table was published in 1869.
How did Mendeleev know that there must be undiscovered elements and how did he takethis into account when he designed his periodic table?
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(2)
20
(b) By the early 20th century protons and electrons had been discovered.
Describe how knowledge of the numbers of protons and electrons in atoms allow chemiststo place elements in their correct order and correct group.
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(3)
(c) The transition elements are a block of elements between Groups 2 and 3 of the periodictable.
(i) Transition elements have similar properties.
Explain why, in terms of electronic structure.
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(2)
Page 39 of 57
(ii) There are no transition elements between the Group 2 element magnesium and theGroup 3 element aluminium.
Give a reason why, in terms of electronic structure.
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(1)
(Total 8 marks)
Page 40 of 57
Mark schemes
(a) A base11
(b) forces1
(c) calcium loses electrons and oxygen gains electrons
max 3 for incorrect reference to atom / ion or to oxygen / oxide1
two electrons are transferred1
calcium has a 2+ charge1
oxide has a 2– charge1
[6]
(a) 408 kg12
(b) all points correct
± ½ small square2
allow 1 mark if 5 points correct
best fit line1
(c)
1
5525 dm3
1
(d) relative formula mass of TiCl4 is 1901
25.26 %1
Answer given to 3 significant figures = 25.3 %1
25.23% with or without working gains 3 marks
(e) argon is unreactive1
water (vapour) would react with sodium
allow water (vapour) would react with titanium(IV) chloride1
Page 41 of 57
and air contains oxygen that would react with reactants
allow and air contains oxygen that would react with products1
(f) (titanium conducts electricity) because electrons in the outer shell of the metal atoms aredelocalised
1
and so electrons are free to move
allow the delocalised electrons in the metal carry electrical chargethrough the metal
1
through the whole structure1
[15]
(a) mobile phase propanone13
stationary phase paper1
(b) any three from:
• contains chlorophyll a, b and carotene• contains Pigment B• does not contain pheophytin• contains (at least) one unknown substance• contains five substances• contains a substance that does not dissolve in the solvent
3
(c)
1
(d) both measurements correct
solvent front = 9.0 cm and pigment B distance = 5.0 cm1
Rf = 5.0 / 9.01
= 0.56
allow ecf from incorrect measurements1
(e) origin line drawn in ink1
so it will run or dissolve in the solvent or split up1
spots under solvent or solvent above spots / origin line1
Page 42 of 57
so they will mix with solvent or wash off paper or colour the solvent or dissolve in thesolvent
1
[13]
(a) (i) neutrons
this order only1
electrons1
protons1
(ii) box on the left ticked1
4
(b) (i) effervescence / bubbling / fizzing / bubbles of gas
do not accept just gas alone1
magnesium gets smaller / disappears
allow magnesium dissolves
allow gets hotter or steam produced
ignore references to magnesium moving and floating / sinking andincorrectly named gases.
1
Page 43 of 57
(ii) Marks awarded for this answer will be determined by the Quality ofCommunication (QC) as well as the standard of the scientific response.Examiners should also refer to the information in the Marking Guidance andapply a ‘best–fit’ approach to the marking.
0 marksNo relevant content
Level 1 (1−2 marks)There are simple statements of some of the steps in a procedure for obtainingmagnesium chloride.
Level 2 (3−4 marks)There is a description of a laboratory procedure for obtaining magnesiumchloride from dilute hydrochloric acid and magnesium.
The answer must include a way of ensuring the hydrochloric acid is fullyreacted or a method of obtaining magnesium chloride crystals.
Level 3 (5−6 marks)There is a well organised description of a laboratory procedure for obtainingmagnesium chloride that can be followed by another person.
The answer must include a way of ensuring the hydrochloric acid is fullyreacted and a method of obtaining magnesium chloride crystals.
examples of the points made in the response:• hydrochloric acid in beaker (or similar)• add small pieces of magnesium ribbon• until magnesium is in excess or until no more effervescence occurs *• filter using filter paper and funnel• filter excess magnesium• pour solution into evaporating basin / dish• heat using Bunsen burner• leave to crystallise / leave for water to evaporate / boil off water• decant solution• pat dry (using filter paper).
*Student may choose to use a named indicator until it turns a neutral colour,record the number of pieces of magnesium added then repeat without theindicator.
6
[12]
(a) (i) protons
allow “protons or electrons”, but do not allow “protons andelectrons”
1
(ii) protons plus / and neutrons1
5
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(b) (because the relative electrical charges are) −(1) for an electron and +(1) for a protonallow electrons are negative and protons are positive
1
and the number of electrons is equal to the number of protons
if no other mark awarded, allow 1 mark for the charges cancel out1
(c) (the electronic structure of) fluorine is 2,7 and chlorine is 2,8,7
allow diagrams for the first marking point1
(so fluorine and chlorine are in the same group) because they have the same numberof or 7 electrons in their highest energy level or outer shell
if no other mark awarded, allow 1 mark for have the same / similarproperties
1
(d) S1
(e) (i) ions1
(ii) molecules1
[9]
(a) because this lithium atom has
3 protons1
and 4 neutrons1
mass number is total of neutrons and protons
accept protons and neutrons have a mass of 1
accept number of neutrons = 7 - 3(protons)
ignore mass of electron is negligible1
6
(b) grams
accept g1
12C
allow carbon-12 or C-12
ignore hydrogen or H1
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(c) any three from:
max 2 if no numbers given
numbers if given must be correct
• both have 8 protons
accept same number of protons• 18O has 10 neutrons• 16O has 8 neutrons
accept different number of neutrons or 18O has two more neutronsfor 1 mark
• both have 8 electrons.
accept same number of electrons3
[8]
(a) (iron) is a metal
accept transition element
allow (iron) had different properties (to oxygen and sulfur)
ignore electrons1
7
(b) so that elements with similar properties could be placed together
allow to make the pattern fit
ignore undiscovered elements1
(c) atomic number(s)
allow proton number(s)1
(d) all have one electron in the outer shell (highest energy level)
allow same number of electrons in the outer shell (highest energylevel)
1
(so they) have similar propertiesorreact in the same way
allow specific reactions e.g. with water1
[5]
(a) increase18
(b) (i) Na+ and Br−
both required1
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(ii) sodium chloride
allow NaCl
do not allow sodium chlorine1
(iii) chlorine is more reactive than bromine
allow converse argument
allow symbols Cl, Cl2, Br and Br2
allow chlorine / it is more reactive
do not allow chloride or bromide1
(iv) fluorine
allow F / F2.
do not allow fluoride.1
[5]
(a) Li and K
either order
allow lithium and potassium1
9
(b) Fe
allow iron1
(c) N and As
either order
allow nitrogen and arsenic1
(d) Cu
allow copper1
[4]
(a) 1 × 10−10 m1
10
(b) 1 / one
allow alkali metals1
(c) R and S1
because they have the same number of protons
allow same atomic number, different mass number1
Page 47 of 57
and a different numbers of neutrons1
(d) Level 3 (5–6 marks):A relevant and coherent explanation of the trend in reactivity. The response makeslogical links between the points raised and considers both the number of energy levelsand the distance between the nucleus and the outer energy level.
Level 2 (3–4 marks):Statements that are linked to provide a simple explanation of the trend in reactivity usingeither the number of energy levels or the distance between the nucleus and the outerenergy level.
Level 1 (1–2 marks):Simple statements made about the halogens or the trend in reactivity.
0 marks:No relevant comment
Indicative content
Simple statements / descriptions• have 7 electrons in the outer shell• need to gain an electron• form ions with a -1 charge• halogens further down the group are less reactive (or vice versa)• halogens further down the group have more shells or energy levels (or vice
versa)
Linked statements / explanations• have 7 electrons in the outer shell so need to gain an electron to have the
electronic structure of a noble gas• halogens further down the group are less reactive because they have more
shells or energy levels (or vice versa)• halogens further down the group have more shells or energy levels so less
attractive force on the incoming electron (or vice versa)• halogens further down the group have more shells or energy levels so more
‘shielding’ against the incoming electron (or vice versa)• outer electrons of halogens further down group are further away from the
attractive force of the nucleus (or vice versa)• an electron is less easily gained because there are more shells or energy
levels (or vice versa)• an electron is less easily gained because the outer electrons are further from
the attractive force of the nucleus (or vice versa)6
[11]
(a) density = mass / volume111
Page 48 of 57
(b) any two from:
• no forces shown between spheres• atoms / molecules / ions are not solid spheres• not all the same size.
2
(c) at higher temperatures particles have more kinetic energy1
(so) the (average) speed of the particles increases1
(so there are) more frequent collisions with the wall of the container1
which apply a greater force on wall of container (so pressure rises)1
[7]
(a) most alpha particles went straight through, suggesting lots of empty space112
a few alpha particles bounced back, suggesting small central nucleus1
with all the positive charge1
the plum pudding model does not explain the results because it shows the whole atom as aball of positive charge with no empty space
1
(b) the figures show that the radius of an atom is 10 000 times bigger than the nucleus1
consistent with the nuclear model, which says that the atom has a tiny nucleus at thecentre of the atom
1
(c) all hydrogen atoms have just one proton (in the nucleus)1
some hydrogen atoms also have one neutron1
protons and neutrons have the same relative mass so mass number of these atoms is 21
(d) neutrons are not attracted or repelled by a positive nucleus1
so the neutrons would all pass through the foil1
[11]
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(a) did not appear because they had not been discovered or they are unreactive or they didnot form compounds
1
13
(b) arranged in order of atomic / proton number1
elements in the same group have the same number of electrons in the outer shell1
(c) chlorine>bromine>iodine
table shows that chlorine displaces bromine and iodine1
and bromine displaces iodine1
(d) Cl2(aq) + 2 Br–(aq) Br2(aq) + 2 Cl–(aq)
correct formulae1
correct balancing1
correct state symbol1
(e) the further down the group, the halogen becomes less reactive because outer electrons arefurther from the nucleus
1
so less attractive force on an incoming electron1
[10]
(a) because they form hydroxides114
that give alkaline solutions (in water)1
(b) the atoms have more electron shells (as move down the group)1
so the electron in the outer shell is further away from the nucleus1
which reduces the attraction to the nucleus1
so the electron is lost more easily from the atom1
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(c)
electronic structure of lithium drawn correctly1
electronic structure of oxygen drawn correctly1
correct charge on ions (Li+ and O2–)1
correct number of each ion (2 lithium, 1 oxygen)1
[10]
(a) Sulfur dioxide causes acid rain.115
(b) red / orange / yellow
do not accept any other colours1
because sulfur dioxide (when in solution) is an acid1
(c) (there are) weak forces (of attraction)
do not accept any reference to covalent bonds breaking1
between the molecules
do not accept any other particles1
(these) take little energy to overcome
award third mark only if first mark given1
Page 51 of 57
(d) Marks awarded for this answer will be determined by the Quality of Communication(QC) as well as the standard of the scientific response. Examiners should also referto the information on page 5 and apply a ‘best-fit’ approach to the marking.
0 marksNo relevant content
Level 1 (1 – 2 marks)A relevant comment is made about the data.
Level 2 (3 – 4 marks)Relevant comparisons have been made, and an attempt made at a conclusion.
Level 3 (5 – 6 marks)Relevant, detailed comparisons made and a justified conclusion given.
examples of the points made in the response
effectiveness
• W removes the most sulfur dioxide• D removes the least sulfur dioxide
material used
• Both W and D use calcium carbonate• Calcium carbonate is obtained by quarrying which will create scars on
landscape / destroy habitats• D requires thermal decomposition, this requires energy• D produces carbon dioxide which may cause global warming / climate change• S uses sea water, this is readily available / cheap
waste materials
• W product can be sold / is useful• W makes carbon dioxide which may cause global warming / climate change• D waste fill landfill sites• S returned to sea / may pollute sea / easy to dispose of
6
[12]
(a) (i) any one from:
• one electron in the outer shell / energy level• form ions with a 1+ charge
1
16
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(ii) any one from:
• hydrogen is a non-metal• (at RTP) hydrogen is a gas• hydrogen does not react with water• hydrogen has only one electron shell / energy level• hydrogen can gain an electron or hydrogen can form a negative / hydride
/ H–ion• hydrogen forms covalent bonds or shares electrons
accept answers in terms of the Group 1 elements1
(b) (i) (bromine) gains electrons
it = bromine
do not accept bromide ion gains electrons
ignore loss of oxygen1
(ii) I2must both be on the right hand side of the equation
1
+ 2e–
2I– – 2e– ➔ I2 for 2 marks1
(iii) fluorine is the smallest atom in Group 7 or has the fewest energy levels inGroup 7 or has the smallest distance between outer shell and nucleus
the outer shell must be mentioned to score 3 marks1
fluorine has the least shielding or the greatest attraction between the nucleusand the outer shell
1
therefore fluorine can gain an electron (into the outer shell) more easily1
[8]
Page 53 of 57
(a) weaker bonds
allow (other substances) react with the silicon dioxide
or
fewer bonds
ignore weaker / fewer forces
or
disruption to lattice
do not accept reference to intermolecular forces / bonds1
(b) (i) Na2O
do not accept brackets or charges in the formula1
(ii)
electrons can be shown as dots, crosses, e or any combination
2 bonding pairs
accept 4 electrons within the overlap1
2 lone pairs on each oxygen
accept 4 non-bonding electrons on each oxygen1
(c) lattice / regular pattern / layers / giant structure / close-packed arrangement1
(of) positive ions or (of) atoms1
(with) delocalised / free electrons
reference to incorrect particles or incorrect bonding or incorrectstructure = max 2
1
[7]
17
(a) Will kelp last longer than coal as an energy source?118
Page 54 of 57
(b) any two from:
• cannot be determined by experiment
allow can’t predict how long kelp / coal will last
allow more testing needed
• based on opinion
• ethical or environmental or economic reason
allow could damage ecosystem allow reference to cost2
(c) (i) 71
(ii) sodium (atom) loses (electron) and iodine (atom) gains (an electron)
reference to incorrect bonding or incorrectly named particle= max 2
any or all marks can be obtained from a labelled diagram
ignore inner shell electrons if shown1
1 electron1
(electrostatic) attraction or forms ionic bond(s)1
(iii) ions can move (in the solution)1
(iv) 2 I – I 2 + 2 e –
1
(v) hydrogen is formed1
because sodium is more reactive (than hydrogen)1
[11]
(a) reference to incorrect bonding or incorrect structure or incorrect particles = max 3
giant structure / lattice
ignore many bonds1
19
made up of positive ions surrounded by delocalized / free electrons
allow positive ions surrounded by a sea of electons1
Page 55 of 57
with strong bonds / attractions
allow hard to break for strong1
so a lot of energy is needed to break these bonds / attractions / forces
ignore high temperature
ignore heat1
(b) (i) that they are very small
or
1-100 nanometres or a few(hundred) atoms
accept tiny / really small / a lot smaller / any indication of very smalleg. microscopic, smaller than the eye can see
ignore incorrect numerical values if very small is given1
(ii) delocalised / free electrons
allow sea of electrons1
one non-bonded electron from each atom
accept electron(s) moving through the structure / nanotube
allow electron(s) carry / form / pass current / charge1
[7]
(a) if placed consecutively, then elements would be in wrong group / have wrong properties
allow some elements didn’t fit pattern1
20
left gaps1
(b) (elements placed in) atomic / proton number order1
(elements in ) same group have same number of outer electrons1
any one from:
• number of protons = number of electrons
• reactions/(chemical) properties depend on the (outer) electrons
• number of shells gives the period
allow number of shells increases down the group1
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(c) (i) (transition elements usually) have same / similar number of outer / 4th shellelectrons
allow 2 electrons in outer shell1
(because) inner (3rd ) shell / energy level is being filled
ignore shells overlap1
(ii) 2nd shell / energy level can (only) have maximum of 8 electrons
accept no d-orbitals
or2nd shell / energy level cannot have 18 electrons
1
[8]
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