Questions Q1.

An atom of phosphorus contains 15 electrons. Describe how these 15 electrons are arranged in a phosphorus atom.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. Q2. (a) Complete the table to show the relative mass of a neutron and of an electron.

(2)

(b) Complete the sentence by putting a cross ( ) in the box next to your answer. An atom has no overall charge because it contains

(1) A more protons than electrons B the same number of electrons and protons C the same number of electrons and neutrons D more neutrons than electrons

(c) The atomic number of lithium is 3. The mass number of an atom of lithium is 7.

State the name and number of each of the particles in the nucleus of this atom. (2)

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Q3.

The atomic number of oxygen is 8.

The mass number of an atom of oxygen is 17. Describe the number and type of particles in the nucleus of this atom.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. Q4.

Elements and atoms

Beryllium, Be, has atomic number 4.

(a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer. From its position in the periodic table (page 2), beryllium is most likely to be a

(1) A metal B halogen C compound D gas at room temperature

(ii) Give the symbol of an atom of another element in the same period of the periodic table as beryllium.

(1)

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(b) The atomic number of beryllium is 4.

The mass number of an atom of beryllium is 9. (i) State the numbers of protons, electrons and neutrons in this atom of beryllium.

(3) ............................................... protons ............................................... electrons ............................................... neutrons

(ii) Complete the sentence by putting a cross ( ) in the box next to your answer.

The relative charge on an electron is (1)

A +1 B 0 C −1 D −2

(c) The electronic configuration of phosphorus is 2.8.5.

Explain, in terms of its electronic configuration, why phosphorus is in group 5 of the periodic table. (2)

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(Total for question = 8 marks) Q5.

Sulfur and oxygen are both in group 6 of the periodic table. Explain, in terms of their electronic configurations, why they are both in group 6.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. Q6.

The periodic table is very useful to chemists. (a) Complete the sentence by putting a cross ( ) in the box next to your answer.

The periodic table is a table of (1)

A mixtures B elements C compounds D solutions (b) Complete the sentence by putting a cross ( ) in the box next to your answer.

Group 1 in the periodic table contains (1)

A transition metals B noble gases C halogens D alkali metals (c) The table shows some of the gases in group 0 and some of their properties. The gases are shown in the order in which they appear in group 0.

(i) Fill in the three spaces in the table.

(ii) Some light bulbs contain a metal filament.

These light bulbs are filled with argon. Explain why argon, instead of air, is used inside these light bulbs.

(2) .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. ..............................................................................................................................................

(d) The table shows some solids and some properties of solids. Draw one straight line from each solid to properties of that solid.

(Total for Question = 9 marks)

Q7.

Answer the question with a cross in the box you think is correct . If you change your mind about an answer, put a line through the box and then mark your new answer with a cross .

Which of the following is true for most metals? (1)

A they are dull

B they have low melting points

C they are found on the right-hand side of the periodic table

D they are malleable

(Total for question = 1 mark) Q8.

Complete the sentence by putting a cross ( ) in the box next to your answer. The particles in atoms are electrons, neutrons and protons. The mass of an electron is

(1) A greater than the mass of a neutron B the same as the mass of a proton C smaller than the mass of a proton D the same as the mass of a neutron

Q9. A carbon atom contains 6 electrons, 7 neutrons and 6 protons.

(i) State the mass number of this carbon atom. (1)

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(ii) Give the electronic configuration of this carbon atom. (1)

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(Total for question = 2 marks)

Q10. Figure 4 shows information about the charges and relative masses of the three subatomic particles.

Figure 4

Use the information to give the names of particles A, B and C. (2)

particle A

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particle B

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particle C

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(Total for question = 2 marks)

Q11. The equation for the reaction that occurs in the Haber process is

N2 + 3H2 2NH3

(i) Use the periodic table to give the number of the group and of the period of nitrogen. (2)

group

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period

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(ii) State what is meant by the symbol in the equation. (1)

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(Total for question = 3 marks)

Q12.

The periodic table is very useful to chemists. Complete the sentence by putting a cross ( ) in the box next to your answer.

The periodic table is a table of (1)

A mixtures B elements C compounds D solutions

Q13. Figure 5 shows a diagram of an atom of sulfur.

Figure 5

(i) State why this atom of sulfur has an atomic number of 16 and a mass number of 32. (2)

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(ii) Give the electronic configuration of an atom of sulfur. (1)

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(Total for question = 3 marks)

Q14. Many elements are useful in everyday life.

The mass of a sample of pure gold is compared to the mass of a sample of an alloy of gold. The two samples have the same total number of atoms but the alloy of gold contains both gold atoms and silver atoms.

What is the description and explanation for the mass of the alloy compared to the mass of pure gold?

Use the periodic table to help you. (1)

The sample of the alloy is

A heavier because silver atoms are heavier than gold atoms

B lighter because silver atoms are lighter than gold atoms

C unchanged because the number of atoms is the same

D unchanged because atoms have a negligible mass

(Total for question = 1 mark) Q15. * Here is some information about the periodic table.

In the periodic table elements are arranged in rows and columns. The position of an element in the periodic table depends on its atomic structure. Elements with similar chemical properties are found in the same parts of the periodic table.

Identify different parts of the periodic table and explain how the position of an element in the periodic table is linked to its chemical properties and atomic structure.

(You are provided with an outline of the periodic table below and you may use this to help your answer.)

(6)

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Examiner's Report Q1. Generally, this question was answered well; most candidates scored both marks sometimes by the inclusion of a correct electronic configuration diagram. Occasionally seen was references to shells of atoms e.g. 2 atoms on first shell. There were some vague responses such as the electrons were 'around the nucleus' or 'in circles dotted around the nucleus'. Some candidates gave incorrect shells such as 2, 10, 5 with incorrect numbers of electrons that the shells could hold.

Results Plus: Examiner Comments The answer was helped with the inclusion of the electronic configuration diagram. This was given 2 marks.

Results Plus: Examiner Comments Although there was a clear electronic configuration diagram to aid this answer, there was some confusion as to where the electrons were located. Unfortunately the candidate had thought the inner circle of the diagram was part of the nucleus, and so only the mark for the correct number of electrons in the outer shell could be given.

Results Plus: Examiner Tip Learn the maximum number of electrons that can be held in an electron shell and how the electronic configuration can be worked out.

Q2. (a)

A large number of candidates failed to score marks here because they gave answers which clearly referred to the relative charges rather than the relative masses which were asked for.

Results Plus: Examiner Comments Responses like this were very common. The candidate has answered in terms of the relative charge of the particles when the question asked for relative masses.

Results Plus: Examiner Comments This response was worth both marks.

(c)

It was evident that there was some confusion about the meaning of atomic number and mass number with many getting the numbers of protons and neutrons mixed up. Many candidates also listed electrons in their answer but did not clarify they were not in the nucleus.

Results Plus: Examiner Comments This candidate has correctly stated 3 protons and 4 neutrons but has also mentioned electrons so was only awarded 1 mark.

Results Plus: Examiner Comments This answer was given both marks because although electrons were mentioned, the candidate made it clear that they were not in the nucleus.

Q3. Many candidates answered this question very well giving the expected answer of 8 protons and 9 neutrons in the nucleus. Candidates sometimes just stated 8 protons, 9 neutrons and 8 electrons, implying, probably without intending to do so as they did not make a clear enough distinction between the nucleus and the rest of the atom, that the nucleus contained all three sub-atomic particles. Poor maths was evident in the processing of the numbers of particles: candidates also confused atomic number and mass number and therefore obtained incorrect values for the numbers of protons and of neutrons.

Unfortunately in this question, many candidates had not comprehended the significance of the information about the oxygen atom given in the question. This question was about the oxygen-17 isotope and was deliberately chosen so it was clear how the numbers of protons and neutrons had been obtained. Some candidates thought they should point out what they perceived as an error and gave the answer of 8 protons and 8 neutrons – they achieved one mark for this. Doing

this they showed that they did not understand the difference between the terms 'relative atomic mass' (as given on the periodic table) and 'mass number' (as referred to in the question), since only the mass number could give the total number of protons and neutrons.

Results Plus: Examiner Comments Evidence of poor maths skills. One mark scored for the correct number of protons.

Results Plus: Examiner Comments Several answers were seen like this. It was not clear if they understood where the electrons were located in an atom. Answers like this scored one mark, as the presence of the electrons stopped the awarding of the second mark.

Results Plus: Examiner Comments Here is an example of an answer where the candidate had wrongly corrected the mass number of the oxygen atom. In this case the answer then went on to describe the electron arrangement and showed they did not understand the arrangement of particles in an atom. This answer scored 0 marks.

Results Plus: Examiner Comments Although here the candidate pointed out a perceived error, they then chose to ignore it and obtained two marks for the correct answer.

Results Plus: Examiner Tip Learn the difference between relative atomic mass and mass number. Learn the basic properties of the sub-atomic particles - mass, relative charge and location.

Q4. (a)(ii)

Many candidates could write the symbol for an element in the same period as beryllium. However, a significant number of candidates were confused between a group and a period and they wrote Mg or Ca as their answer.

(b)(i)

A significant number of candidates were unable to work out the numbers of protons, electrons and neutrons in an atom of beryllium. Candidates should learn how to work out the numbers of protons, electrons and neutrons in an atom from the atomic and mass numbers.

(c)

The majority of candidates were able to relate the group number to the number of electrons in the outer shell. Only a small number of candidates referred to proton, neutrons or atoms in the outer shell. Some candidates just referred to 'it has 5 at the end of the configuration' without explaining what the 5 refers to. Only a few candidates wrote about the similar properties of elements in the same group.

Results Plus: Examiner Comments

This answer did not score any marks as it did not refer to electrons or outer shell.

Results Plus: Examiner Tip Read the information given in the question. The electronic configuration of phosphorus is given as 2.8.5. The question asks you to use this electronic configuration in your answer.

Results Plus: Examiner Comments This answer scored 1 mark for writing about the outer shell. Neutrons are in the nucleus of an atom. There was a clue in the question. Electronic configuration is the arrangement of electrons in an atom.

Results Plus: Examiner Tip Learn the positions of the particles in an atom.

Results Plus: Examiner Comments This is a good answer, scoring 2 marks.

Q5. This question was answered generally well, with many scoring 2 marks. Of the correct answer the majority were of the type stating that both oxygen and sulfur were in group 6 because their atoms had 6 electrons in the outer shell and the minority were of the type where their atoms both needed two more electrons to fill the outer shell.

Common errors included references to them being in group 6 as they were both gases or noble/Nobel [sic] gases. There was frequent reference to the atomic number and mass number e.g. those of sulfur being double that of oxygen: 8 → 16 or 16 → 32. Often a reference was made to oxygen and sulfur having same properties, qualities or reactivity or to them both being non-metals, gases or non-conductors. In these instances, the candidates were not answering the question as given.

Results Plus: Examiner Comments This did not answer the question and scored 0 marks.

Results Plus: Examiner Comments This was a very good answer scoring 2 marks.

Results Plus: Examiner Comments One of a number of common errors seen in the marking of this question. 0 marks given.

Results Plus: Examiner Tip Understand how the electronic configuration of an atom of an element is related to the position of that element in the periodic table.

Q6. (c) (i) (1)

Although the majority of the candidates could offer suitable values for the density of argon, a blank space was the usual cause for the mark not being awarded.

(c) (i) (2)

A large majority of the candidates scored the mark here, and invariably an incorrect answer was down to giving the symbol of krypton incorrectly as 'KR' or as 'kr'.

(c) (i) (3)

Again a large majority of the candidates followed the pattern of reactivity correctly and gave a correct answer of 'no reaction'; of the remainder quite a few blank spaces were seen and several answers of 'reaction' were given.

(c) (ii)

Many candidates scored at 1 mark, usually for mentioning something about lack of reactivity, but only a small percentage of candidates were able to explain this lack reactivity to score the second mark. Many answers included irrelevant properties such as density or electrical conductivity. It was clear that many candidates did not understand the role of argon in a light bulb. Several thought that the argon was reacting with the metal filament and giving out light as a result. Some thought that using argon made the lighter brighter than if air had been used. Overall, almost half of the candidates scored at least 1 mark.

Results Plus: Examiner Comments This answer indicated that argon was so unreactive that it did not react with anything - for this, 1 mark was awarded.

Results Plus: Examiner Comments The candidate thought that argon was a metal and did not understand the purpose of its presence in a light bulb. There was nothing here to credit.

Results Plus: Examiner Comments Several answers of this type were seen where candidates thought that the argon made the light shine brighter. No marks were awarded here.

Results Plus: Examiner Tip Learn the simple properties of the group 0 elements and be able to explain the lack reactivity in terms of full shells of electrons.

(d)

It was disappointing to see the number of candidates who could not match up the properties of the elements with the correct element, with only about half the candidates scoring at least one mark on this question. Often iodine was matched with the yellow solid and copper matched with the grey solid. Q7. No Examiner's Report available for this question Q8. No Examiner's Report available for this question Q9. (i)

Candidates found this question quite difficult with only the best being able to state the mass number of the carbon atom. Many candidates added all three values to give an answer of 19.

Results Plus: Examiner Comments This example shows a very common incorrect answer.

Results Plus: Examiner Comments This example shows the correct answer that was awarded 1 mark.

(ii)

As with part (i), candidates found giving the electronic configuration of the carbon atom quite difficult. Many gave the number of electrons rather than the electronic configuration.

Results Plus: Examiner Comments Many candidates gave the number of electrons in the carbon atom rather than the electronic configuration of the atom.

Results Plus: Examiner Comments This example of the correct answer was awarded 1 mark.

Q10. No Examiner's Report available for this question Q11. No Examiner's Report available for this question Q12. No Examiner's Report available for this question Q13. No Examiner's Report available for this question

Q14. No Examiner's Report available for this question Q15. It was very pleasing to see so many good responses with nearly half of the candidates reaching Level 2. The basic structure of the periodic table was generally well known with many correctly identifying and naming some groups. There was however a lot of confusion evident from weaker candidates with groups being described as being rows, and the stepped line on the diagram was sometimes thought to be separating solids and liquids or gases.

Good information about the atomic structure and chemical properties aspects was much less common than information about parts of the periodic table. The increasing reactivity down group 1 and the inertness of the noble gases were the most frequently mentioned points about chemical properties. A number of candidates failed to gain much credit as they mainly wrote about Mendeleev and the history of the periodic table. Only the best candidates described the elements as being arranged in order of increasing atomic number and the link between the period number and the number of shells.

Results Plus: Examiner Comments There is a lot of correct information in this answer with reference to different parts of the periodic table, including on the diagram. Also the link between the position of an element in a group and its electronic configuration was very well made as was a link to trends in chemical reactivity. Hence the candidate was awarded a Level 3 and 6 marks.

Results Plus: Examiner Comments This answer contains references to several parts of the periodic table but in addition only one other relevant aspect i.e. elements ordered by atomic number. It was worthy of Level 2 and awarded 4 marks.

Results Plus: Examiner Comments This candidate correctly identified the position of transition metals but unfortunately mixed up groups and periods. The identification of non-metals as only group 7 is not totally correct. It was awarded Level 1 and 2 marks.

Mark Scheme Q1.

Answer Acceptable answers

Mark

A description to include • 2.8 (in 1st and 2nd shell)(1) • 5 (in outer shell)(1)

suitable diagram in place of 2.8(1).5(1) electrons in shells / orbits / rings(1)

(2) Q2.

Q3.

Answer Acceptable answers

Mark

An description linking • 8 protons (1) • (and) 17-8/9 neutrons (1)

ignore references to electrons in shells / charges on particles if electrons in nucleus max 1 protons and neutrons with incorrect numbers (1) (2)

Q4.

Q5.

Answer Acceptable answers

Mark

Explanation linking • (both have) same number (of electrons) in outer shell(1) • 6 (electrons in outer shell) (consequent on first point) (1)

correct electronic configurations or diagrams alone max 1 'they both have 6 in the outer shell' scores both marks allow 'both need 2 (more) (electrons) to fill outer shell' for both marks (2)

Q6.

Answer Acceptable answers

Mark

(a) B elements (1) (b) D alkali metals (1)

(c)(i) 1 any value in range 1.45 to 2.99

any answer which, to 1 sf, is in the range (1)

(c)(i) 2 Kr Reject KR, kr (1) (c)(i) 3 no reaction 'nothing' (1) (c)(ii) An explanation

linking any two of: • argon is inert / unreactive (1) • argon does not react with metal/filament/metal/ filament would react with air or oxygen / ORA (1) • atom has eight electrons in outer shell / full (outer) shell (1)

ignore noble gas doesn't react with anything argon does not corrode the metal ignore references to electrical conductivity

(2) (d)

all 3 correct – 2 marks any two correct – 1 mark one correct – 0 marks

if two answer lines from one element, then ignore

(2) Q7.

Q8.

Answer Acceptable answers

Mark

C smaller than the mass of a proton

(1)

Q9.

Q10.

Q11.

Q12.

Answer Acceptable answers

Mark

B elements (1) Q13.

Q14.

Q15.