BTEC Level 3 National in Applied
Science: Chemistry
First teaching September 2016
Sample Marked Learner Work
External Assessment
Unit 1: Principles and Applications of Science I
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Guidelines and tips
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community
Ask the community for help and clear up your study doubts
University Rankings
Discover the best universities in your country according to Docsity users
Free resources
Our save-the-student-ebooks!
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
Unit 1: External Sample Marked Learner Work, Study Guides, Projects, Research of Chemistry
BTEC Level 3 National in Applied. Science: Chemistry. First teaching September 2016. Sample Marked Learner Work. External Assessment. Unit 1: Principles and ...
Typology: Study Guides, Projects, Research
2021/2022
1 / 34
This page cannot be seen from the preview
Don't miss anything!
Related documents
Partial preview of the text
Download Unit 1: External Sample Marked Learner Work and more Study Guides, Projects, Research Chemistry in PDF only on Docsity!
BTEC Level 3 National in Applied
Science: Chemistry
First teaching September 2016
Sample Marked Learner Work
External Assessment
Unit 1: Principles and Applications of Science I
In preparation for the first teaching from September 2016 and as a part of the on-going support that we offer to our centres, we have been developing support materials to help you better understand the application of Nationals BTEC Level 3 qualification.
What is Sample Marked Learner Work (SMLW)?
The following learner work has been prepared as guidance for centres and learners. It can be used as a helpful tool when teaching and preparing for external units.
Each question explores two responses; one good response, followed by a poor response. These responses demonstrate how marks can be both attained and lost.
The SMLW includes examples of real learners’ work, accompanied with examiner tips and comments based on the responses of how learners performed.
Below are two boxes and a tips section displaying the format. Each question will show a learner response, followed by comments on the command verbs and the content of the question. Tips may be offered where possible.
The appendix has attached a mark scheme showing all the possible responses that perhaps were not explored in the SMLW, but can still be attained.
Tips offer helpful hints that the learner may find useful. For example:
Recommended length of the answer Reference to the amount of marks awarded General advice for the learner when answering questions
The red box comments on the command verbs used in the question. Command typically means; to instruct or order for something to be done. Likewise, in assessments, learners are required to answer questions, with the help of a command verb which gives them a sense of direction when answering a question.
This box highlights the command verb used and comments if the learner has successfully done this, or not.
The green box comments on the content words and phrases. Content makes reference to subject knowledge that originates from the specification. Learners are required to use subject specific knowledge to answer the questions in order to gain maximum marks.
The comments include:
Any key words/phrases used in the learner’s answer. Why has the learner gained x amount of marks? And why/how have they not gained any further marks? Any suggestions/ ideas regarding the structure of the answer. If the answer meets full marks- why it is a strong answer? What part of the content has been mentioned to gain these marks?
The command verb or phrase should help the learner to understand what is required.
If the question is worth 1 mark only a brief one sentence definition is needed.
Good response: The command verb here is ‘describe’. The learner is required to look at a graph and describe the trends in the electronegativity. The question does not ask for an explanation, so all that is needed is a simple answer which states that electronegativity increases across a period and decreases down a group. This learner has used the command verb correctly.
Good response: This question targets A2 Understand the physical properties of elements – electronegativity. The learner has given both marking points in a concise answer so can be awarded both marks. It is obvious that the ‘It’ referred to in the question means the electronegativity so the marks can be awarded. As a general rule though the use of ‘it’ should be avoided as in some cases it is ambiguous and learners may lose marks. It is better to always state what they are referring to rather than using the word ‘it’ in their answers.
2
Question 6a ii Describe the trends in electronegativity in the periods and groups of the periodic table [Total marks for Q6aii= 2 marks]
0
Question 6a iii: State the three factors that affect the electronegativity of an element. [Total marks for Q6aiii= 2 marks]
Good response: The command verb here is ‘state’. This command verb requires just a statement of fact. No explanation or description is required. The learner has understood the command verb and given three simple statements.
Good response: This question targets A2 Understand the physical properties of elements – electronegativity. The learner has stated two of the mark scheme answers in points 2 and 3 and has therefore scored two marks. The first factor is not correct as it would be atomic size and not molecular size that would affect the electronegativity. However in this case atomic size would not score a third mark as it is the same marking point as atomic radius, which has already been awarded a mark. The correct answer that would have scored the 3rd mark is nuclear charge.
0
2
Poor response: Non-metals are generally more electronegative than metals but the answer is too vague. Electronegativity depends on the number of inner electron shells and not the number of electrons in the outer shell. If the learner had said the size of the atom rather than the size of the element for the 3rd factor they would have scored the first marking point, but again this is too vague an answer so no marks can be awarded here.
Poor response: The learner has stated three facts but unfortunately they are not correct answers to this question.
When asked to state 3 factors, answers should be brief and time not wasted giving explanations.
State normally requires the learner to recall knowledge and if they have revised thoroughly this type of question should be easy.
Poor response: This learner has been awarded 1 mark for the mention of a dipole- dipole bond, which is another way of saying that the bond is polar, which is an acceptable answer on the mark scheme. The learner cannot be awarded an explanation mark here as they have has described what a dipole-dipole bond is but not explained why it is present in nitrogen (IV) oxide or why it leads to permanent dipole-dipole forces.
Hydrogen bonds are not present here, as there is no hydrogen in the molecule of nitrogen (IV) oxide and the description of the hydrogen bond is also incorrect.
1
Poor response: The learner has given two types of intermolecular force, one of which is correct, but there is no explanation as to why there are dipole-dipole forces present.
In a question where the learner is asked for two explanations, they need to give 2 examples with a justification for each.
The information in the stem of the question is usually there to help the learners answer the question. Encourage learners to read this information carefully and underline key facts and data.
Question 7b i: Explain the arrangement of the electrons in the third energy level of silicon. [Total marks for Q7bi= 3 mark]
Good response: The command word is ‘explain’ which requires justification as to why the electrons are arranged as they are in the 3rd^ energy level of silicon. The learner has addressed this by giving the electron configuration and explaining the difference in the energy levels of the electrons.
Good response: This question targets A1 Structure and bonding – understand electronic structure of atoms and A2 understand the electronic arrangement of elements using s, p, d notation. The learner has given the full electron configuration of silicon although only the 3rd^ energy level electrons needed to be present for the first mark. They have given a partial explanation in terms of the difference in energy, which gains the second mark, but in order to gain all 3 marking points they should have explained that the electrons in the p orbital do not pair up and fill the orbitals singly as 3px^1 and 3py^1 , so 2 marks awarded.
0
2
Question 7b ii: Explain why the first ionisation energy of silicon (789 KJ mol-^1 ) is greater than that of germanium (762 KJ mol-^1 ).
[Total marks for Q7b ii= 2 marks]
Good response: The command verb here is ‘explain’. The data is given in the question and the learner needs to give a linked explanation as to why the ionisation energies are different, which this learner has done.
Good response: This question targets A2 Understand the physical properties of elements – reasons for trends in ionisation energy down Groups. The learner has stated that germanium has an extra shell of electrons on it, which gains the 1st marking point. The learner has also explained this by saying, so the force between the nucleus and the outer electrons is less than that of silicon, which gains the 2nd marking point. Attraction would have been a better word to use than force, but it is clear what the learner means so the word force has been accepted here. This is a good explanation and both marks can be scored here. It is the reverse argument to what is stated in the mark scheme and this is acceptable as it clearly explains the difference in ionisation energies.
2
0
Poor response: The learner has used the periodic table at the back of the paper to look up the positions of silicon and germanium in order to determine what periods they are in and hence how many shells of electrons each element has. It is not true that silicon has fewer electrons in the outermost shell as silicon and germanium are in the same group so they both have four electrons in the outer shell. For elements in the same group the ionisation energy differs because of the number of shells not because of the number of electrons in the outer shell. Even if the learner had given a correct statement about the number of shells they would not have gained the second mark as they have not explained why this affects the ionisation energy.
No marks can be scored here.
Learners must be encouraged to use the Periodic Table provided to help them with questions where data on specific elements is given.
In a 2 mark explain question such as this a linked explanation needs to be given.
Poor response: The learner has given one piece of information which unfortunately is incorrect and there is no explanation as to why this would make a difference to the ionisation energies, so the command verb has not been addressed.
Poor response: It is true that there is an ionic bond in calcium chloride, but this is not an acceptable answer here as the question asks for the type of force and the learner must say that it is an electrostatic force to gain the mark. In this case even if the learner had named the force correctly they would still have not gained a mark. This is because they have also written intermolecular force, which is incorrect and therefore would negate any correct answer given. No marks can be awarded here.
When a question asks the learner to state the name of something only a simple one or two word answer is required.
Learners should never give more than one answer in a question like this as a wrong answer could lose them the mark which could have been gained for the correct answer.
Question 8b: Draw-dot-and cross diagrams to show the arrangement of the outer electrons in the calcium ion and the two chloride ions in calcium chloride, CaCl 2 [Total marks for Q8b= 2 marks]
2
Good response: The command verb here is ‘draw’. The learner has correctly drawn the calcium ion and the two chloride ions that she has been asked to draw.
Good response: This question targets A1 Structure and bonding – Understand ionic bonding: electronic configuration diagrams of cations and anions. The learner has gained both marks here as they have drawn the ions asked for with the correct number of outer shell electrons in each case, which gains the first marking point. The learner has also given the correct charges on the ions for the second marking point. It is important that learners read the full question. This question asks for outer shell electrons only and this learner has not wasted time drawing the inner shells.
0
Question 8c: Calculate the maximum mass of calcium chloride, CaCl2, that can be produced when 500kg of calcium carbonate, CaCO3, reacts with excess dilute hydrochloric acid
[Total marks for Q8c = 3 marks]
3
Good response: The command verb here is ‘calculate’. This requires the learner to use mathematical processes to produce a numerical answer. This learner has calculated the maximum mass correctly.
0
Poor response: The learner has found the Mr for calcium carbonate and 111 is also written in the box, which is the Mr of calcium chloride, but there is no indication as to where this number has come from.
The learner has not used the equation to find the mole ratio so cannot score the first marking point. The second marking point is for using the 100, 111 and 500 correctly in a mathematical expression, which they have not done and the third marking point is for the correct answer of 555kg. As the answer is incorrect and how they obtained it is not shown, they cannot have the third marking point, so no marks can be awarded.
When doing calculations the learners should always show their working, setting the steps out clearly. If an error is made in their working, the error can be carried forward and some marks can still be awarded.
If an equation for a reaction is given before a calculation question it is likely that the learners will need to use this equation to do the calculation.
Good response: This question targets A1 Structure and bonding- Understand the quantities used in chemical reactions: reacting quantities. The learner has used the equation to find the correct 1:1 mole ratio which is the first marking point. They have then looked up the relative atomic masses using the periodic table and hence calculated the Mr values correctly. They have used these values to calculate the correct answer and so both the second and third marking points can be awarded, therefore all 3 marks have been scored. The layout of the answer is a little unusual as it appears to be back to front, but this has not detrimentally affected the answer as the working is clearly shown. In all calculations it is important that learners show their working as they may gain marks for an early step even if they get the final answer wrong.
0
Poor response: The learner has made a start at the calculation by finding the Mr of calcium carbonate, but unfortunately this alone is not creditworthy.