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Question 1

What are the properties of the alkali metals?

Answer 1

 They are soft and can be cut by a knife. Softness increases
going down the group.

 They have a low density.

Lithium, sodium and potassium float on water.

 They have low melting and boiling points. Their melting /boiling
points decrease as we go down the group.

alkali metals do also share some properties with typical metals:

 They are good conductors of heat and electricity.

 They are shiny. This is only seen when alkali
metals are freshly cut.

Question 2

Why does the reactivity of alkali metals increase when going down the group?

Answer 2

 The outer shell electron of each atom gets further away from the nucleus (because there are more filled shells between the nucleus and the outer electron).

 More shells creates more shielding

 This means that the force of attraction between the positive nucleus and the outer electron gets weaker as you go down the group. So, the outer electron is more easily lost during chemical
reactions

 The more easily the outer electron is lost, the more reactive the alkali is

Question 3

why do we call the Group 1 elements ‘the alkali metals’?

Answer 3

when they react with water reaction forms alkaline hydroxides.

Question 4

What is the trend for the reaction of alkali metals with
water?

Answer 4

Lithium reacts steadily with water

Sodium reacts vigorously with water and may burn with a yellow flame.

Potassium reacts violently with water and burns with a lilac flame.

Caesium reacts explosively with water

Question 5

Name each Halogen, its state at room temperature and its color.

Answer 5

Florine - Gas - Pale yellow

Chlorine - Gas - Pale green

Bromine - Liquid - Brown

Iodine - Solid - Dark Grey

Question 6

State the test for Chlorine gas.

Answer 6

Use a Damp blue Litmus Paper ——-> turn red then bleach white the chlorine is present

Question 7

What does Inert mean?

Answer 7

Unreactive

Question 8

What are the uses for Argon (Ar)?

Answer 8

1. To put out fires in computer rooms –non-flammable, high density gas, relatively inert
2. Inside filament lamps to stop the hot filament reacting with oxygen relatively inert
3. In welding to stop the hot metal reacting with oxygen in the air –non [[yflammable, relatively inert

Question 8

What are the uses for Neon (Ne)?

Answer 8

In making long lasting illuminated signs –produces a distinctive red-orange light when electricity is passed

Question 8

What are the uses for Helium (He)?

Answer 8

In airships and party balloons –low density gas, relatively inert, non
flammable

Question 9

What are the uses for Krypton (Kr)?