Which is the hardest metal among the alkaline and alkaline earth metals?

Question

Which is the hardest metal among the alkaline and alkaline earth metals?

Answer 1

Lithium is the hardest alkali metal.

http://www.speclab.com/elements/lithium....

Not sure about alkaline earth, although I would think beryllium.  However, radium has the highest density, so it would be the heaviest.  That might not translate to hardness though.  All the alkaline earth metals are pretty soft, and none are found free in nature, unlike the alkali metals.

http://www.chemicalelements.com/groups/a...