प्रश्न-अभ्यास|f-BLOCK|Lanthanide Series (58-71)|Actinide Series (90-103)|Reactions of f-block Elements|लेंथनॉइड एवं एक्टनॉइड में अंतर|प्रश्न-अभ्यास

The elemnts cerium (Z = 58) and neptunium (Z = 93) belong to f-block elements.

The f - block consists of …… series.

Ions of Lanthanide and actinide series have unpaired electrons in the (n - 2) f orbital and hence they are

ZnSO4 || CuSO4 || FeSO4 || F Block ( Lanthanide and Actinide)

Variation OF Size in F-block || Size in Isoelectronic Series || Ionisation Energy and its Variation

प्रश्न अभ्यास |H.C.F. और L.C.M. के कुछ गुण |प्रश्न अभ्यास |OMR

H.C.F. और L.C.M. के कुछ गुण |प्रश्न अभ्यास |OMR|प्रश्न अभ्यास

Assertion: the 4f^(-) and 5f^(-) inner transition series of elements are placed separately at the bottom of the modern periodic table. Reason : (i) Position of f-block elements prevents the undue expansion of the mordern periodic table, ie, maintains its structure. (ii) Position of f-block elements preserves the principle of classification by keeping elements with similar properties in a single column.

In the modern period table, elements are arranged in order of increasing atomic number which is related to the electric configuration. Depending upon the type of orbitals receving the last electron, the elements in the periodic table have been diviced into four blocks viz s,p,d and f. The modern periodic table consists of 7 periods and 18 groups. Each period being with the filling of a new energy shell. In according with the Aufbua principle, the seven periods (1 to 7) have 2,8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanodis and actionoids are placed at the bottom of the main body of the periodic table. The last element of p-block in 6th period is represented by the outermost electronic configuration.