Write the general outer electronic configuration of s-, p-, d- and f- block elements.

Use the periodic table to answer the following questions.

A. Identify an element with five electrons in the outer subshell.

B. Identify an element that would tend to lose two electrons.

C. Identify an element that would tend to gain two electrons.

D. Identify the group having metal, non-metal, liquid as well as gas at the room temperature.

The increasing order of reactivity among group 1 elements is Li < Na < K < Rb <Cs whereas that among group 17 elements is F > CI > Br > I. Explain.

Assign the position of the element having outer electronic configuration

(i) ns²np⁴ for n=3 (ii) (n-1)d²ns² for n=4, and (iii) (n-2) f⁷ (n-1)d¹ns² for n=6, in the periodic table.

The first (∆_iH₁) and the second(∆_iH₂) ionization enthalpies (in kJ mol^–1) and the electron gain enthalpy (in kJ mol^–1) of a few elements are given below:

Which of the above elements is likely to be?

A. the least reactive element.

B. the most reactive metal.

C. the most reactive non-metal.

D. the least reactive non-metal.

E. the metal which can form a stable binary halide of the formula MX₂(X=halogen).

F. the metal which can form a predominantly stable covalent halide of the formula MX (X=halogen)?