How do you tell if something is a strong base?

[Lucy Weaver 1K]

I know that group 1 metal hydroxides and group 1/2 metal oxides are strong bases, but does anyone know the chemical properties that make them such?

[Bailey Giovanoli 1L]

I'm sure there is more technicality to it, but typically strong bases are alkali metal oxides and hydroxides (group 1), as well as alkaline earth metal oxides and hydroxides (group 2).

[Jessie Hsu 1C]

Strong bases are bases that can ionize completely in water, which suggests that there needs to be a big difference in electronegativity between the metal and oxygen in the metal oxide/hydroxide.

[Edward Tang 1k]

Group 1 metal hydroxide is a strong base because the bonds between the hydroxide and metal is weak(as said above, big difference in electronegativity), therefore they dissociate in water and release hydroxides which are strong proton acceptors.

Group 1/2 metal oxides work in a similar fashion, except they first react with water to form the metal hydroxides said above, for example in Na2O+H2O=2NaOH.