THE PERIODIC TABLE

1
THE PERIODIC TABLE

• Objectives
• To be able to identify groups and periods in the
  periodic table
• To know the positions of group1, group 0 and
  group 7 in the periodic table
• To know the positions, properties and uses of the
  halogens
• Read through the slides and then complete the
  linked worksheets

2
THE PERIODIC TABLE

• The rows across the elements in the periodic
  table are called periods
• The columns down are called groups.
• The groups are numbered from 1 to 8
• Group 8 is also called group 0.

3
SOME GROUPS

• Group 1 are found on the far left side and are
  called the alkali metals
• Group 7 are found at the right hand side and are
  called the halogens.
• Group 8 are also known as group 0 and are called
  the noble gases

4
GROUP 7

• These elements are all non- metals.
• They are also called the halogens
• They are-
• Fluorine
• Chlorine
• Bromine
• Iodine

5

• They have low melting points (this means that the
  change from a solid to a liquid at a low
  temperature)
• They do not conduct electricity
• They go around as pairs of atoms.
• We call them diatomic molecules
• We write them like this
• Fluorine - F2
• Chlorine - Cl2
• Bromine - Br2
• Iodine - I2

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What are they like?

• Fluorine is a very pale yellow gas
• Chlorine is a green gas
• Bromine is a dark red brown liquid
• Iodine is a black shiny solid

7
THE REACTIONS OF THE HALOGENS

• The halogens like to take
• part in chemical reactions
• The react with metals to
• make salts
• The most reactive halogen
• is fluorine and the least
• reactive is iodine.
• They get less reactive
• as you go down the group

• The halogens like to take part in chemical
  reactions
• The react with metals to make salts
• The most reactive halogen is fluorine and the
  least reactive is iodine.
• They get less reactive as you go down the group

• most
• reactive
• Least
• reactive

8
Uses of the halogens

• Iodine is used as an antiseptic
• Chlorine is used in swimming pools to kill
  bacteria
• Fluorine is used in tooth paste
• Bromine is used photographic film

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Click here and complete the worksheetClick
here to complete the reactions of the halogens
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Click here to go to part 3