2.b - Group 7 (halogens)

Question 1

what do group 7 elements form

Answer 1

diatomic molecules ( go round in pairs) eg. Cl2 and Br2

Question 2

what is the state and colour of chlorine at room temp.

Answer 2

green gas

Question 3

what is the state and colour of bromine at room temp.

Answer 3

red-brown liquid

Question 4

what is the state and colour of iodine at room temp.

Answer 4

dark grey ( crystalline) solid

Question 5

what happens as the atomic number of halogens increases

Answer 5

elements have a darker colour and a higher boiling point

Question 6

as you go down the group 7 metals what happens ( in terms of reactivity )

Answer 6

become less reactivity

Question 7

definition of a displacement reaction

Answer 7

a more reactive element ‘pushes out’ ( displaces ) a less reactive element from a compound

Question 8

Need to know the displacement reaction table for
chlorine,
bromine,
iodine ,

and potassium chloride
potassium bromide
potassium iodide

Answer 8

???

CGP pg.37

Question 9

explain the trend in reactivity in Group 7 in terms of electronic configuration

Answer 9

1. Halogen only needs to gain 1 electron
2. easier it is for halogen atom to attract an electron= more reactive
3. as you go down halogens = less reactive
4. harder yo attract the extra electron when it is further away from the nucleus ( i.e. when there are more shells) because atomic radius = larger