Tiêu đề 8.THE d- AND f-BLOCK ELEMENTS.pdf ✅

ChemContent | D and F Block Elements ChemContent 1 Introduction to d-block elements • In the periodic table the d block consist of the elements of group 3 to 12. • The d orbital of the d-block elements in four periods are filled. • The three series of the transitionmetals are 3d series from Sc to Zn, 4d series from Y to Cd and 5dseries from La • to Hg. • The fourth 6dseries begins from Ac and is incomplete till now. Position of d-block in periodic table
ChemContent | D and F Block Elements ChemContent 2 • The d-block elements are found in the middle section of s- and p- block elements in the periodic elements. • This lead to its name ‘transition’ due to its position between s- and p- block elements. Electronic Configurations of the d-Block Elements • The electronic configuration of d-block elements is(n-1) d1–10 ns1–2 . They have two incomplete outershells. • Where (n–1) = Inner d orbitals having electrons from 1-10. • ns = Outermost orbital may have one or two • (n-1) d10 n s2 represents the electronic configurations of Zn, Cd and Hg. • They exhibit variable valency that differ by units of one.
ChemContent | D and F Block Elements ChemContent 3 Physical Properties • The transition metals are hard and tough. They have low volatility but Zn, Cd and Hg are an exception. • They have high melting and boilingpoints due to the greaterquantity of electrons from (n- 1) d along with the ns electrons metallic Fig. The trends in melting point of d-block elements. • Metals possessing high boiling point are noble in their • The metals belonging to second and third series have greater enthalpies of atomisation than the elements belonging to first series.
ChemContent | D and F Block Elements ChemContent 4 Fig. Enthalpies of atomisation Metallic characteristics: • All transition metals exhibit metallic character. • They are good conductors of heat and electricity. Fig. Metal is used at the tip of the plug that is inserted into the socket • They are hard and tough. • Being metal they exhibit the property of malleability, ductility and sonorousity. Fig. Aluminium is beaten into thin sheets to make aluminium foil used to pack food (Malleability)