Outermost electronic configuration | Group Number | Oxidation state |
$$3s^{2}\ 3p^{4}$$ | $$16$$ | $$\underline { a }$$ |
$$3s^{1}$$ | $$\underline { b }$$ | $$+1$$ |
$$2s^{2}\ 2p^{5}$$ | $$\underline { c } $$ | $$\underline { d } $$ |
$$3d^{10}4s^{2}$$ | $$\underline { e } $$ | $$\underline { f } $$ |