topic 6- group 7 - periodic table

Recall the colours and physical states of chlorine, bromine and

iodine at room temperature

Chlorine - yellow-green gas

Bromine - red-brown liquid

Iodine - purple solid

Describe the pattern in the physical properties of the

halogens, chlorine, bromine and iodine, and use this pattern to

predict the physical properties of other halogens

There is a trend in state change as you go down the group. This is because the melting and boiling points increase as you go down the group.

From this, you can predict that any halogens above chlorine will be gases (due to low boiling points), and any below iodine will be solids (due to high m/p)

Describe the chemical test for chlorine

When damp litmus paper is put into chlorine gas, the litmus paper is bleached and turns white.

Describe the reactions of the halogens, chlorine, bromine and

iodine, with metals to form metal halides, and use this pattern

to predict the reactions of other halogens

The pattern shows a more reactive halogen can displace a less reactive one, but a less reactive one cannot displace a more reactive one

what do halogens,chlorine,bromine and iodine form

hydrogen halids which dissolve in water to form acidic solutions

Describe the relative reactivity of the halogens chlorine,

bromine and iodine, as shown by their displacement reactions

with halide ions in aqueous solution, and use this pattern to

predict the reactions of astatine

pt of previous

Explain why these displacement reactions are redox

reactions in terms of gain and loss of electrons,

identifying which of the substances are oxidised and

which are reduced

redox is when a reaction gain and loses electrons

Explain the relative reactivity of the halogens in terms of

electronic configurations

The reactivity of halogens decreases as you go down Group 7 because the atomic radius increases, making the outermost shell further from the nucleus.