Periodic Classification And Periodic Properties Ques 23
The first ionisation potential of nitrogen and oxygen atoms is related as follows.
$(1989,1 \mathrm{M})$
(a) The ionisation potential of nitrogen is less than the ionisation potential of oxygen
(b) The ionisation potential of nitrogen is greater than the ionisation potential of oxygen
(c) The two ionisation potential values are comparable
(d) The difference between the two ionisation potential is too large
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Answer:
Correct Answer: 23.(a)
Solution:
- (a) and (b) are infact the same statements and both are correct. N has slightly greater ionisation energy than oxygen which is against periodic trend. This exception is due to completely half-filled $\left(2 p^{3}\right)$ orbital in nitrogen that makes ionisation slightly more difficult than oxygen.
(c) Although $\mathrm{N}$ has a greater first ionisation potential than oxygen, the two values are comparable because they are adjacent in a period, i.e., electrons are removed from the same orbit during ionisation.
(d) Incorrect - opposite to (c). of the bonded atoms which in turn exhibits a periodic trend in the long form of the periodic table.
BETA
