Group 17 of periodic table consists of five elements, i.e., fluorine, chlorine, bromine, iodine and astatine. These elements are called Halogens. Fluorine is most reactive and hence is also called super halogen. Astatine is radioactive and hence occurs in nature only in traces.
The elements of Nitrogen family i.e. group 15 of the periodic table are: nitrogen (N), phosphorous (P), arsenic (As), antimony (Sb) and bismuth (Bi). Collectively, group 15 elements are called pnictogens and their compounds are called pniconides. (It means suffocation producing elements)
Coordination compounds are the compounds in which the central metal atom is linked to a number of ions or neutral molecules by coordinate bonds, i.e., by donation of lone pairs of electrons by these ions or neutral molecules to the central metal atom.
D- block elements are called transition elements since they have unpaired electrons in their d orbital.
Elements in which last electron ( also called differentiating electron ) enters the ante-penultimate energy level are called F-Block elements . These elements have also been called inner transition elements
