Increasing order of electronegativity is:
A) Bi < P < S < Cl
B) P < Bi < S < Cl
C) S < Bi < P < Cl
D) Cl < S < Bi < P

Hint: Electronegativity is the tendency of an element to withdraw electrons from its neighbouring atoms or elements. In the periodic table generally, electronegativity increases moving from left to right, across the period and decreases moving down the group, from top to bottom.

Complete answer:
Determine the group and period number of all given elements.



Out of the elements given to us, element bismuth is present on the right side of the periodic table in the sixth period and while other elements (Phosphorous, sulphur, Chlorine) are present in the third period of the periodic table.
Now, using the position of elements in the periodic table we can determine the increasing order of electronegativity as follows:
> As per the trend of electronegativity, electronegativity increases moving from left to right, across the period and decreases moving down the group, from top to bottom. Hence the element present down in the group will have less electronegativity and if elements are present in the same period then the element present to the right side of the periodic table will have more electronegativity.
> Here, Bismuth is present in V A group and sixth period whereas other elements are placed in the top of the periodic table in the third period of the periodic table. Hence bismuth will have at least electronegativity than other elements due to its position in the periodic table.
> Now elements phosphorus, sulphur and chlorine are placed in the same period but different groups according to the position of elements in periodic table chlorine is placed to the extreme right in the periodic table among the rest 3 elements hence chlorine will have the highest electronegativity before chlorine sulphur is placed hence it will have the second largest electronegativity and at the third position will be the phosphorous.

Thus, the increasing order of electronegativity in element follows the order as follows:
Bismuth < Phosphorus < Sulphur < Chlorine.

Hence, the correct option is option A.

Note: Electronegativity increases moving from left to right, across the period and decreases moving down the group, from top to bottom. Halides are more electronegative than other elements because they are placed right in the periodic table and more affinity to attract the shared pair of electrons.