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Classification of Elements and Periodicity in Properties
Why does the first ionsiation enthalpy increase as we go from left to right through a period of the periodic table?
Or
How does ionisation enthalpy vary along a period?
In general, ionisation enthalpy increases as we move from left to right across a period.
Reason:
We know that on moving across the period from left to right.
(i) the nuclear charge increases,
(ii) progressive addition of electrons occurs in the same enthalpy level and
(iii) atomic size decreases.
Thus, due to the gradual increase in nuclear charge and the simultaneous decrease in atomic size, the valence electrons are more and more tightly held by the nucleus. Therefore, more and more enthalpy is needed to remove the electron and hence ionisation enthalpy keeps on increasing.
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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?
What is the name given to the s-block elements?
To which block the element with outer electronic configuration 4s23d10 belongs?
Why are there 10 elements in each series of d-block?
In terms of electronic configuration,
what is common in a given period and group?
Give the general electronic configuration of
(i) Transition elements (ii) Inner transition elements.
Name the group and period to which an element with Z = 15 belongs ?
What are the advantages of periodic classification of elements?
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