Group 7 elements Flashcards
What are group 7 elements known as?
Halogens
How does the boiling and melting point change as you go down group 7?
Why?
It increases.
The forces of attraction between the diatomic molecules becomes stronger and requires more energy to break.
(RAM increases = size of molecule increases.)
What is a halogen?
These are the diatomic molecules in group 7.
They end in -ine
Eg. Bromine
What is a halide?
These are ions of group 7 elements (found in a compound)
They end in -ide
Eg. bromide
What happens to the reactivity as you go down group 7?
Decreases
What is a displacement reaction in group 7?
Displacement reaction is when a more reactive halogen takes the place of a less reactive halogen and displaces it from its compounds.
How do you know the colour change from a displacement reaction?
Look at the different colours for the halogens
What are the products of potassium iodide + chlorine?
What is the colour change?
Potassium chloride+ iodine
Pale green to Purple/ brown
Explain why fluorine and chlorine are in the same group of the periodic table.
Give the electronic structures of fluorine and chlorine in your explanation. (2)
1.) Fluorine electronic structure 2,7
2.) Chlorine electronic structure 2,8,7
3.) Both have 7 electrons on outer shell, in same group
When can a more reactive halogen displace a less reactive halogen?
- When one of the halogens is in an aqeous solution of the salt.
What colour is fluorine?
Pale yellow
What colour is chlorine?
- Pale green
What colour is bromine?
- Orange
What colour is iodine?
Pink/ purple
What colour is astatine?
- Black
