The Group 1 Elements

Question 1

Explain why group 1 elements are stored under oil?

Answer 1

Because they react with air and react vigorously with water

Question 2

Describe the reaction of lithium, sodium and potassium with water

Answer 2

• hydrogen is formed
• an alkali is formed which is the hydroxide of the metal
• the reactivity with water increases down group 1
• potassium gives a lilac flame

Question 3

Recognise sodium, lithium and potassium as Group 1 elements

Answer 3

They can be recognised by the colours they produce in a flame test

Question 4

Recall the flame test colours for lithium, sodium and potassium compounds

Answer 4

Lithium - red
Sodium - yellow
Potassium- lilac

Question 5

Explain why group 1 elements have similar properties

Answer 5

Because when they reatc, an atom loses one electron to form a psotive ion with a stable electronic structure

Question 6

Describe how to use a flame test to identify the presence of lithium, sodium and potassium compounds

Answer 6

• use of moistened flame test wire
• flame test wire dipped into solid sample
• flame test wire put into blue bunsen flame
• colours of the flames

Question 7

Predict the physical properties of rubidium or caesium given information about the other group 1 elements

Answer 7

The reaction would be very fast, exothermic, violent snd caesium is even more reactive and will react violently with water

Question 8

Explain why a process is oxidation from its ionic equation

Answer 8

Oxidation involves the loss of electrons from an atom

Question 9

Explain why the Group 1 elements are known as the alkali metals

Answer 9

Because the first three elements in the group are lithium, sodium and potassium. They all have one electron in their outer shell which means they have similar properties.