Worksheet 3.13
The Periodic Table: the halogens
Sarah is diving into a swimming pool. She can smell chlorine.
1
a Explain why there is chlorine in the swimming pool.
b Iodine is in the same group of the Periodic Table as chlorine. Give a use of iodine.
2
Chlorine and iodine are in Group VII of the Periodic Table.
a What name is given to Group VII elements?
b Is chlorine a metal or a non-metal?
c Is iodine a metal or a non-metal?
d Name a type of organic life that is a source of iodine?
© Cambridge University Press 2014 IGCSE® Chemistry
Worksheet 3.13
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a The atomic number of chlorine is 17. What key information does this tell you about chlorine?
b i
ii
What is the electron arrangement of chlorine?
How many electron shells does it have?
iii What period is it in?
c Iodine has five electron shells. How many electrons are in the outer shell of iodine?
4
The symbol for chlorine is Cl, iodine is I and sodium Na.
Chlorine combines with sodium to make sodium chloride, NaCl.
Iodine also reacts with sodium.
What will be the name and formula of the compound formed?
© Cambridge University Press 2014 IGCSE® Chemistry
Worksheet 3.13
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