Modern inorganic chemistry

13 The transition elements

(Scandium to zinc)

PHYSICAL PROPERTIES OF THE ELEMENTS

In the periodic table, the elements from scandium to zinc in Period 4
lie between calcium in Group II and gallium in Group III. These
elements are termed transition elements (deriving from the use
of this word by Mendeleef) or d-block elements, because in them the
inner 3d energy level is filling up. Similar blocks of elements occur
in Periods 5 and 6 (p. 9) Table 13.1 suggests that the transition
elements of Period 4 should end at nickel, because in the next two
elements, copper and zinc, the 3d energy levels are full. In fact

Table 13.1

ELECTRONIC CONFIGURATIONS OF THE ELEMENTS

Element Atomic number Electronic configuration

Sc

Ti

v

Cr

Mn

Fe

Co

Ni

Cu

Zn

21 [Ar~

22 [Ar'

23 [AV

24 [Ar"

25 [Ar=

26 [Ar^5

27 [Ar=

28 [Ar=

29 [Ar=

30 [Ar~

3d^1 4s^2

3d^2 4s^2

3d^3 4s^2

3d^5 4sl

3d^5 4s^2

3d^6 4s^2

3d^7 4s^2

3d* 4s^2

3dln4sl

3c/^10 4.v^2

359