Which one of the following will have more no of electrons? Na/ K

Which one of the following is more basic?

Which one of the following will have largest number of atoms?

Which one of the following will have a low heat of fusion ?

Which of the following ions have same number of unpaired electrons?

Which of the following ions have same number of unpaired electrons ?

Which one of the following is a correct electronic configuration of sodium ?

General electronic configuration of actionoids is [Rn] 5f^(1-14) 6d^(0-1) 7s^2 . Which of the following actionoids have one electron in 6d orbital ?