The transition metals sometimes form nonstoichiometric compounds. These compounds have (a) definite structures and definite proportions

Indefinite structures and indefinite proportions. 48. The maximum number of unpaired electrons is present in (a) Fe (b) Cu (c) Co (d) Ni The number of unpaired electrons in ions is as follows, Ion Valence shell configuration Unpaired electrons Fe 6 2 3d 4s 4 Cu 10 1 3d 4s 1 Co 7 2 3d 4s 3 Ni 8 2 3d 4s 2 So, Fe an atom contains maximum unpaired electrons. Thus, (a) is the correct option. 49. The stability of ferric ion is due to (a) half-filled f-orbitals (b) half-filled d-orbitals (c) completely filled f-orbit