# Why are the melting and boiling points of the group 1 metals lower than the group 2 metals in the same period?

I thought it was because the group 1 metals are smaller than the group 2 metals but the answer sheet says it's because there are more valence electrons and a stronger positive charge in group 2 metals. But why does it matter if there's more valence electrons and a stronger positive charge?

In the photo, you can see that for Group $2$ metals, the cation is doubly positively charged, making the attraction stronger.