Strong Bases

[Megan Singer 3D]

Does anyone know why all of the alkaline earth metals form metal hydroxides that are strong bases except Be and Mg? It seems to me that since they're in the same group they would also form strong bases

[Andrew Dao 3C]

I believe that Be and Mg have small bonds that are very strong and hard to break in order to be strong bases, similar to how the halogens are all strong acids except for hydrofluoric acid (HF), which has a small and strong bond.

[Vance Liu]

We classify strong bases by their ability to dissociate into cations and OH- ions in water. Since Mg and Be form strong bonds with OH-, it is harder for them to dissociate in water thus making them weaker bases. Same thing with HF, which has very strong bonding, making it a weak acid.

[SuryaDham 3E]

beryllium and magnesium form strong and short bonds with OH-, thus OH- does not normally dissociate from Be or Mg, making them weak bases.

[Matthew Vu 3C]

It's probably because beryllium hydroxide and magnesium hydroxide, due to their shorter bond lengths, will not dissociate completely.

[Ryan Khiev 1L]

Like Matthew said, the shorter the bond the stronger the bond, so less of their molecules dissociate to form hydroxide in water compared to other strong bases.

[Neha Mukund]

I believe that since Be and Mg have shorter and smaller bond lengths, they are weak bases because weak bases do not dissociate completely. This means that the hydroxide ion will not dissociate from Be or Mg.

[Mario Prado 1K]

Hello,

Be and Mg have smaller and stronger bonds with (OH-) which makes it harder for them to be separated thus making them a weak base because they cannot easily dissociate.

Hope this helps

[Sabira Mohammed 3I]

Be and Mg are the smaller atoms and would form a stronger bond with OH-, so they aren't strong bases because they don't dissociate as completely as the others do. This is similar to how HCl, HBr, and HI are strong acids but HF isn't.

[Gianna Greco 1G]

Hi! Be and Mg are weak bases because it is harder for them to disassociate. This is because they have shorter and stronger bonds with (OH-).