Question

which of the following........the smallest size first Na+ II MG +and third Al3 +

Answer 1

Al3+ hv the smallest size coz the larger positive nuclear charge will hv a smaller r

Answer 2

We have that in a period from left to right the atomic radius decreases. So in the period of Na,Mg,Al comparing these three we. Have Al with smaller size so aluminum is the smallest.

And. Now even if we take the ions of the elements- Na+ ,Mg+ and Al+3. Al+3 has the smallest size as the no of +ve nuclear increases the size of the cation decreases as the nucleus attracts the electrons to itself.



Hope this helps.