Group 2 Flashcards
What do all group 2 elements in common?
They have 2 electrons in their outer shell
What happens when group 2 elements react?
They lose 2 electrons and form 2+ ions
M(g) –> M(g)2+ + 2e-
What is the trend for the atomic radius down the group?
The atomic radius increases down the group
Why does the atomic radius increase?
There are extra electron shells as you go down the group
What is the trend for the first ionisation energy down the group?
The first ionisation energy decreases down the group
What factors cause the first ionisation energy to decrease?
- Each element down group 2 has an extra electron shell compared to the one above
- The inner shells shield the outer electrons from the attraction of the nucleus
- The outer electrons are further away from the nucleus which reduces the force of attraction
What is the trend in the reactivity down the group?
The reactivity increases down the group
Why does the reactivity increase down the group?
When the elements react, they lose electrons.
The easier it is to lose electrons, the more reactive the element
In group 2, when is it easier to lose electrons?
First and second ionisation energies
What is the general trend for melting points down the group?
The melting points generally decrease down the group
What type of structure does group 2 element have?
They have a giant metallic structure with positive ions surrounded by delocalised electrons from the outer electron shells
Why do the melting points decrease down the group?
The larger the ionic radius, the further away the delocalised electrons are from the nucleus and the lower the force of attraction.
Therefore, less energy is needed
Why is there a large drop in the melting point between beryllium and magnesium?
The metallic structure changes
What other name is given to group 2?
Alkaline Earth metals
Why is group 2 called alkaline earth metals?
Their oxides and hydroxides are alkaline
