Among which of these element pairs is the increase in radius minimum?

Which of these element pairs possess nearly the same atomic radius?

Which of these element pairs possess nearly the same atomic radius?

Among which of the following pairs of elements, the first one has lesser ionisation energy than the second-

Among the alkali metals, which element has the largest atomic radius ?

Among the alkali metals, which element has the lowest ionic radius ?

Among the following pairs, in which one from first species to second species decrease in radius is maximum

Among the groups of transition elements, the ionic radius increases with an increases in atomic number. Justify.

The minimum increase in covalent radius is from