Question
Chemistry Question on Classification of elements & periodicity in properties
The atomic size generally increases across a period and decreases down the group. Atomic size depends upon valence shell electronic configuration.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
If both assertion and reason are false.
Solution
Along a period, effective nuclear charge increases more than the shielding of inner electrons and thus the size of the atom decreases. Along a group, as the size of the shell increases and so is the shielding of inner electrons, thus down the group the size of the atom increases downwards. Both Assertion and Reason are incorrect.