Element Groups

• Alkali metals
• 1 electron on outer shell
• Very reactive
• Soft
• Low Density
• Form 1+ ions

As you go down the group, reactivity increases

As you go down the group, Boiling and melting points decrease

As you go down the group, Relative atomic mass increases

Reacts with oxygen to produce metal oxide

Reacts with Chlorine to produce metal chlorides  (white salts)

Reacts with Water to produce metal hydroxides + hydrogen

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• Halogens
• 7 electrons in outer shell
• Fluorine - very reactive - poisonous yellow gas
• Chlorine - fairly reactive - poisonous dense green gas
• Bromine - dense, poisonous, red-brown volatile liquid
• Iodine - dark grey crystalline solid or a purple vapour

As you go down the group...

Reactivity decreases

Boiling and melting point increases

Relative atomic mass increases

Form molecular Compounds by covalent bonding

Form 1- ions called halides by reacting with metals - ionic bonding

Displacement reaction happens between a halogen and the salt of a less reactive one

• Noble Gases
• unreactive ( inert )
• colourless at room temp
• monatomic gases - single atoms not bonded
• non - flammable

As you go down the group...

Reactivity stays the same (non reactive)

Boiling and melting points increase

Realative atomic mass increases