Question

Using the periodic table only, arrange the elements in each set-in order of increasing EN:

(a) S, O, Si;

(b) Mg, P, As.

Short answer

Electronegativity is defined as an atom's proclivity to attract the shared pair of electrons between the bonded atoms. Except for noble gases, the electronegativity of an element decreases as we move down a group due to an increase in atomic size or an increase in the number of energy levels, which pushes the valence shell electrons away from the nucleus, whereas it increases as we move across a period.

Step-by-step solution

Electronegativity between S, O, Si

O and S are both present in the same group (group-16), and as we move down the group, the EN decreases, so O's EN is greater than S's. S and Si are both present during the same period, but Si is in group 14 and S is in group 16. It is well known that electronegativity increases from left to right along a period. As a result, the EN of S is greater than that of Si. Si is the least abundant EN element.

As a result, the increasing order of EN is given below.

Si < S < O

Increasing order of Electronegativity between Mg, P, As

As you move to the right side of the periodic table, electronegativity increases.

Mg < As < P.