AL Chem

1.
consider how a covalent bond can be formed. it requires "sharing of electrons between 2 atoms".
now consider the iodine ATOM. it has 5s2 5p5 ; 1 single bond can be formed by using the unpaired electron in a 5p orbital. no other bonds can be formed as other valence electrons are already paired.

now, by excitation of 1 electron from a paired 5p orbital (to a higher-energy orbital, say, 6s), there're 2 singly-occupied 5p and one singly-occupied 6s -- 3 orbitals for bond forming (after hybridization etc.).
when bonded with 3 more-electronegative atoms like O or F, O.N. could raise from +1 to +3.

same explanation for other ON, until all 7 valence electrons are excited to higher energy levels, yielding 7 unpaired orbitals (for hybridization..) .


2.
same group as Cu, Ag and Au. same group.
you'd expect it to be a shiny metal (with metallic luster); less reactive than gold toward oxidation / attack of water, acid etc.

atomic number 111 for roentgenium (Rg)
it is under Ag