Question

For each of the following series, list the species in the appropriate order.

            a) Na, K, K⁺     (Increasing size)

            b) S, Cl, Cl^-      (decreasing size)

            c) Mg, Ca, Ba   (most negative to least negative electron affinity)

            d) Mg, Si, Cl    (increasing First ionization energy)

            e) Be, F, O,      (least negative to most negative electron affinity)

Arrange the elements Sr, In and Te in the order of

Increasing atomic radius

Increasing first Ionization energy

Increasing electron affinity

            Now, Explain clearly the reason for the order chosen by you in each case.

a) b) c)

Answer 1

a ) K > K+ > Na

b)   Cl- > S > Cl

c) most negative Mg and lease negative Ba

d) Cl > Si > Mg

e) F -most negaitive , Be -least negative

f)

atomic radius :    Sr > In > Te

in a period form left to right atomic radius decreases. due to high shielding

first IE      Sr < In < Te

atomic size decreases IE increases

electron affinity :    Sr < In < Te

atomic size decreases electron affinity increases