2(b) Group 7

Question 1

name of group 7 elements?

Answer 1

halogens

Question 2

are they poisonous?

Answer 2

yes

Question 3

are they diatomic? what does it mean?

Answer 3

yes which means they form pairs of atoms sharing electrons (forming a single covalent bond between 2 halogen atoms)

Question 4

fluorine? (state and colour at room temp)

Answer 4

gas
yellow

Question 5

chlorine? (state and colour at room temp)

Answer 5

gas
pale green

Question 6

bromine? (state and colour at room temp)

Answer 6

liquid
red-brown (readily evaporates to from a brown gas - volatile)

Question 7

iodine? (state and colour at room temp)

Answer 7

solid
black (sublimes to form a purple gas)

Question 8

what happens to the melting and boiling points of halogens as you go down the group?

Answer 8

• it increases due to increasing intermolecular forces as the atoms become larger

Question 9

how to reactivity change as you go down the G7?

Answer 9

decreases in reactivity

Question 10

what is a metal hallide?

Answer 10

the ionic compounds that are formed when halogens react with some metals

Question 11

non metal hallide?

Answer 11

the halogens react with non-metals to from simple molecular covalent structures

Question 12

displacement reaction?

Answer 12

occurs when a more reactive halogen displaces a less reactive halogen from an (aq) solution

Question 13

adding chlorine solution to colourless KBR or KI what happens?

Answer 13

• a displacement reaction occurs:
• the solution becomes orange as bromine is formed
• the solution becomes brown as iodine is formed

Question 14

adding bromine solution to colourless KI?

Answer 14

• displaces iodide to iodide and brown is seen