Group 2 - Alkaline Earth Metals Flashcards
As you go down Group 2 what happens to the atomic radius?
It increases
The atomic radius increases as you go down the group, this is because of the extra shell being added.
How many electrons do group 2 elements have in their outer shell?
2
What ions do group 2 elements form?
2+
As they can lose 2 electrons from their outer shell
What Happens the first ionisation energies as you go down group ? (General trend)
It decreases
Why do the first ionisation energies decrease?
More shielding as more shells
Further away from positive nucleus ( larger atomic radius)
So less attraction so electron can be removed more easily
Which has a higher first ionisation energy, Magnesium or Calcium?
Magnesium
What is the trend in reactivity in group 2?
It increases down the group
As Outer electrons more easily lost
Why a is the trend in melting point in group 2?
It decreases down the group
What is the general structure of group 2 elements?
Typical metallic structure with positive ions in a crystal structure with delocalised electrons and held together by electrostatic attraction?
Where do the delocalised electrons come from?
The outer shell
Why does the melting point decrease down group 2?
Metal ions get bigger but the number of delocalised electrons stays the same as does the charge (2+)
Means larger ionic radius so delocalised e- further away from nuclei
So take less energy to overcome the bonds
Why is there a change in the general trend in melting point in group 2 when you get to magnesium ?
The crystal structure arrangement changes
The higher the ionisation energy of a group 2 elements, the less readily it will react. Calcium and strontium react with dilute hydrochloric acid. Which reaction would you expect to occur rapidly?
Strontium
Which sub shell block are alkaline earth metals part of?
s block
They are group 2 elements
