physical properties

Question 1

what do halogens exist as?

Answer 1

diatomic molecules

Question 2

state the appearances of F, Cl, Br and I at room temp

Answer 2

F = pale yellow gas
Cl = pale green gas
Br = brown liquid
I = grey solid which sublimes to purple vapor

Question 3

describe the trend in boiling point down the group

Answer 3

• increases
• atomic radius and relative mass increase
• so london forces are stronger so more energy required

Question 4

describe the trend in electronegativity down the group

Answer 4

• decreases
• atomic radius and shielding increase
• so nuclear attraction decreases and electrons are less easily gained

Question 5

describe the trend in reactivity down the group

Answer 5

• decreases
• atomic radius increases
• nuclear attraction decreases
• electrons less easily attracted

Question 6

what does the reactivity trend of halogens mean in terms of displacement?

Answer 6

• more reactive halogens displace less reactive halides
• halogens are less easily oxidised down the group so they displace halides LOWER DOWN