Short Answer Type
Long Answer TypeShort Answer TypeLong Answer TypeShort Answer TypeLanthanoides and actinodes are placed in separate rows at the bottom of the periodic table. Explain the reason for this arrangement.
Long Answer TypeHow will you predict the position of an element in the periodic table?
The period group or block of an element can be predicted from the electronic configuration of the elements.
(i) Period of the element corresponds to the principal qauantum number of the valence shell.
(ii) Block of the element corresponds to the sub-shell which receives the last electron.
(iii) Group is predicted from the number of electrons in the outermost (n) or penultimate (n -1) shell as follows:
For s-block elements, group number is equal to the number of valence electrons (ns electrons).
For p-block elements, group number is equal to 10+ number of valence electrons (ns and np).
For d-block elements, group number is equal to the sum of the numbers of (n - 1)d and ns electrons.
For f-block elements group number is 3.
Short Answer TypeName the block to which the elements with following valence shell electronic configurations belong:
(i) 3s2 3p5
(ii) 3d104s2
(iii) 3p64s2
(iv) 6s2 4f0
(v) 4s1 3d5
Switch
