Group 7 Flashcards
What is group 7 known as
Halogens
What is flourine
Very reactive poisonous yellow gas
What is chlorine
Fairly reactive poisonous dense green gas
What is chlorine
Fairly reactive poisonous dense green gas
What is bromine
Dense, poisonous red-brown volatile liquid
What is iodine
Dark grey crystalline solid or a purple vapour
Order of group 7
F
Cl
Br
I
At
Trend of group 7
- Less reactive
- Harder gaining extra electron
- higher melting and boiling points
- higher relative atomic masses
Why does group 7 become less reactive
Outer shell is further from the nucleus
How many electrons in outer shell
7
What compounds are formed when they react with metals
Group 7 elements form salts when they react with metals. The term ‘halogen’ means ‘salt former’.
What are the compounds formed when they react with non-metals
simple covalent
Describe displacement reactions involving halogens and the solution of their salts. Example chlorine added to sodium bromide solution
When chlorine (as a gas or dissolved in water) is added to sodium bromide solution, the chlorine takes the place of the bromine. Because chlorine is more reactive than bromine, it displaces bromine from sodium bromide.
The solution turns brown. This brown colour is the displaced bromine. The chlorine has gone to form sodium chloride.
Predict some properties from trends down the groups
- Darker in colour down the group
- trend in state from gas to liquid to solid as you go down the group.
- The melting and boiling points then increase as you go down the group.
