group 2 - alkaline earth metals Flashcards
trends in physical + chemical properties
which block are group 2 elements found in?
s-block
the trend in atomic radius across a period
- atomic radius decreases
- more protons
- similar shielding
- stronger nuclear attraction to outer electron
the trend in atomic radius down a group
- atomic radius increases
- more electron shells
the trend in ionisation energy down group 2
- ionisation energy decreases
- no. of electron shells increases
- more shielding
- weaker nuclear attr. to electron in outer shell
the trend in reactivity down group 2
- reactivity increases
- lower 1st/2nd ionisation energies
- loses electrons & forms +ve ions quicker
the trend in melting point down group 2
- melting point decreases
- weaker metallic bonding down group
- as metal ions are bigger
- lower nuclear attr.
- less energy needed to remove outer electron
group 2 bonding
- metallic bonds
- giant lattice of cations
- strong electrostatic forces of attr. between the cations and delocalised electrons
what type of cations do group 2 metals form?
eg. Mg2+
product of metal + cold water –>
(all group 2 elements form this apart from Mg)
metal hydroxide + hydrogen
product of metal + steam –>
metal oxide + hydrogen
appearance of all oxides
white powders
reaction of group 2 elements with water
react more vigorously with water as you go down the group
which group 2 element doesn’t react with cold water?
Mg –> only reacts with steam
test for Mg
- burns with bright flame
- lit splint goes out with squeak and pop
trend in group 2 hydroxide solubilities down the group
increases in solubility
