4.2.1 Group 7 elements Flashcards
(23 cards)
What is the structure and bonding of halogens?
Halogens have simple structures that are covalently bonded.
What are properties of halogens?
- All are diatomic
- Colours get darker down the group
- MP/BP increases down the group
What is the colour of pure fluorine?
Pale yellow
What is the colour of aqueous fluorine?
N/A insoluble in water
What is the colour of pure chlorine?
Pale green
What is the colour of aqueous chlorine?
Colourless
What is the colour of pure bromine?
Brown
What is the colour of aqueous bromine?
Yellow/orange
What is the colour of pure iodine?
Dark grey
What is the colour of aqueous iodine?
Brown
Estimate the colour of pure astatine.
Black
What is the state of fluorine?
Gas
What is the state of chlorine?
Gas
What is the state of bromine?
Liquid
What is the state of iodine?
Solid
What is the state of astatine?
Solid
What are other properties of bromine?
Volatile, releases brown fumes
What are other properties of iodine?
Sublimes, releases purple fumes
What forms when halogens react with metals?
Ionic compounds
When halogens react with metals to form ionic compounds, they change from halogens to…
…halides.
True or false: Halogens get more reactive down the group.
False: they get less reactive
Why do halogens get less reactive down the group?
Atoms have more electron shells, so the extra electron is further from the nucleus, so its attraction to the nucleus is weaker, making it harder for the atom to gain the extra electron.
What is the chemical test for chlorine?
Damp blue litmus paper turns white. This is because chlorine acts as a bleaching agent, so it removes the colour from the paper.
