2.2.1 Trends in Group 2 : Alkaline earth metals Flashcards
1
Q
Noteson Alkaline metals
A
- 2+ charge
- Ionic compounds
- Reducing agents
- Down group more reactive
2
Q
Why do group 2 elements become more reactive going down the group?
A
- Ionisation energy decreases down group
- Nuclear charge increases
- But shielding increases
- Atomic radius increases (greater distance from protons in nucleus to outer electrons)
- So these 2 outweigh the increasing nuclear charge
- Less energy required to lose electrons, so more reactive going down group
3
Q
Examples of how reactivity increases going down group 2?
A
With dilute HCL, bubbles of H2 gas are given off more vigorously.
With oxygen, barium needs to be stored in oil to prevent reacting with O2 in air
4
Q
What are the physical trends going down group 2?
A
- Melting point decreases
- Atomic radius increases
- So attraction between nucleus and bonding electrons decreases
- Causing decrease in melting point