Answer : Option AExplaination / Solution:
In period when we move from left to right in a period atomic radii 1st decreases till nickel then starts increasing so Ni2+ has smallest radii.
Q9.Which of the following metals have only one oxidation state?
Answer : Option BExplaination / Solution:
Al is not a d block element hence it shows only one oxidation state. While rest all others are d block elements which shows variable oxidation state.