halogens

Question 1

the halogens exist as _________ molecules eg Cl2, Br2, I2

Answer 1

diatomic

Question 2

as you go down group 7 the melting and boiling points
_________

Answer 2

increase

Question 3

chlorine is a _________ _______ gas

Answer 3

poisonous green

Question 4

bromine is a poisionous, ___ ______ liquid which gives off an _______ vapour at room temperature

Answer 4

red brown, orange

Question 5

iodine is a _____ _____ crystalline solid which gives off _______ vapour when heated

Answer 5

dark grey, purple

Question 6

how many electrons does a halogen need to gain to form a 1- ion with a stable electronic sturcture

Answer 6

1 electron

Question 7

state and explain the reactivity down group 7

Answer 7

the reactivity decreases because it gets harder to attract the extra electron when its further away from the nucleus.

Question 8

3 uses of chlorine

Answer 8

1) to kill bacteria
2) sterilising water so its safe to drink/swim
3) cleaning products

Question 9

2 uses of iodine

Answer 9

1) sterilise skin before operation as it kills bacteria
2) radioactive forms are used in nuclear medicine

Question 10

what does chlorine and iodine have in common

Answer 10

they’re both toxic