Chemistry – PLC Task
PLC 41 - Assessed Task
Unit No.
Topic Area
Key Concept
Molecular
Structures
Describe and draw diagrams for ionic bonding
2
Difficulty
Name:

Class:
1. The picture shows sodium reacting with chlorine. The reaction forms sodium chloride.
(a) Use words from the box to answer the questions.
compound
element
hydrocarbon
mixture
Which word best describes:
(i) sodium .......................................................................
[1 mark]
(ii) sodium chloride? ........................................................
[1 mark]
(b) When sodium reacts with chlorine the sodium atoms change into sodium ions.
The diagrams below represent a sodium atom and a sodium ion.
Use the diagrams to help you explain how a sodium atom turns into a sodium ion.
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St Peter’s Catholic Comprehensive School – Science Department 2013
Chemistry – PLC Task
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[2 marks]
(c) (i) The diagram below represents a chlorine atom.
When chlorine reacts with sodium the chlorine forms negative chloride ions.
Complete the diagram below to show the outer electrons in a chloride ion (Cl–).
[1 mark]
(ii) Chloride ions are strongly attracted to sodium ions in sodium chloride.
Explain why.
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[1 mark]
2. (a) A tin of red kidney beans contains calcium chloride as a firming agent.
Calcium chloride is an ionic compound which contains calcium ions (Ca2+) and chloride ions (Cl–
).
(i) The diagram on the left represents the electronic structure of a chlorine atom.
St Peter’s Catholic Comprehensive School – Science Department 2013
Chemistry – PLC Task
Complete a similar diagram on the right to represent a chloride ion.
[2 marks]
(ii) Explain how a calcium atom changes into a calcium ion which has a 2+ charge.
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[2 marks]
Total Score
Out of:
Percentage Score
10
TIP – To Improve Progress
How you can make further progress
0-39% = Practice Task 1
40-79% = Improvement Task 1
80%+ = Extension Task 1
St Peter’s Catholic Comprehensive School – Science Department 2013