The Alkali Metals

Group 1 

• they are very reactive 
• soft to cut 
• they are stored in oil 
• the outside of them are dull ( such as a non metal ) 
• when you cut into them they are silver and shiny ( like a metal ) 

because they are very reactive and react with water and oxygen 

• they become more reactive
• they become softer 
• the melting points decrease

When alkali metals are left in oxygen the surface will tarnish ( go dull ) 

Example of reaction : 

Lithium + oxygen --> Lithium oxide

Li + O2 --> Li20

They all have the same reactions and extras:

Lithium 

• movers across the surface of the water
• Fizzes 

Sodium 

• melts when hits the water and turns into a sphere ( ball ) 

Potassium 

• Catches a lilac flame 
• spits at the end 

Sodium + water --> Sodium hydroxide + Hydrogen 

Na + H20 ---> NaOH + H2

Group 7

They go round in pairs 

' Diatomic Molecules '

• their melting and boiling points increase 
• their reactivity decreases 
• they become darker in colour 

example of when a halogen reacts with an alkali metal 

lithium + fluorine --> lithium fluoride

2Li + F2 --> 2LiF

Fluorine 

Fluoride is very reactive, iron burst into flames without being heated 

Chlorine 

iron and chlorine react fiercely, iron is heated first 

Bromine 

iron and bromine react, this reaction has to be heated 

Iodine 

iodine reacts with iron, has to be heated strongly 

Compounds like sodium chloride, potassium iodide are called salts, they are made up of crystals 

the first name of a salt is always a metal ( positive ion ) 

the surname is always a non metal ( negative ion ) 

• dip a piece of nichrome or platinum wire into the salt 
• place into the hottest part of a blue flame #
• look carefully at the flame and observe the colour change 

contains sodium the flame goes orange/yellow

contains potassium the flame goes lilac/pink

contain lithium goes scarlet red 

• place a small spatula of the salt into a test tube 
• add a pipette of diluted nitric acid 
• shake the test tube 
• add a pipette of silver nitrate solution 

white precipitate for chloride 

cream precipitate for bromide 

pale yellow precipitate for iodide