the elements in group 7 - halogens

Question 1

fluorine at room temperature

Answer 1

pale yellow gas

Question 2

chlorine at room temperature

Answer 2

green gas

Question 3

bromine at room temperature

Answer 3

red/brown liquid

Question 4

iodine at room temperature

Answer 4

grey solid

Question 5

astatine at room temperature

Answer 5

black solid

Question 6

describe fluorine’s reaction with iron wool

Answer 6

too dangerous/reactive to do

Question 7

describe chlorine’s reaction with iron wool

Answer 7

• minimal heating required
• iron glows brightly

Question 8

describe bromine’s reaction with iron wool

Answer 8

• more heating required
• iron glows less brightly

Question 9

describe iodine’s reaction with iron wool

Answer 9

• strong heating required
• iron has a small amount of glowing

Question 10

describe astatine’s reaction with iron wool

Answer 10

• very strong heating required

Question 11

explain why reactivity decreases down group 7

Answer 11

• both need to gain 1 electron
• chlorine has more shells than fluorine
• incoming electron is further from the nucleus
• weaker attraction between electron and nucleus
• therefore harder to gain the electron