Classification of Elements and Periodicity in Properties
How 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.
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Give the ‘liquid elements’ in the periodic table.
What is valency of an element?
Gallium was named by Mendeleev as
What are magic numbers?
Which property is the basis of long form of periodic table?
How many elements are placed in each period of the p-block?
What is the number of groups in: (i) p-block (ii) d-block?
How many elements are present in:
(i) second period
(ii) fourth period
(iii) sixth period?
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