Question

write one pair of the isobars why the chemical properties of isobars are not similar

Answer 1

Isobars differ in atomic number (or number of protons) but have the same mass number. Anexample of a series of isobars would be  40Ar, 40K, and 40Ca.

Their chemical properties are different because :-
→Chemical properties depends upon atomic number I.e. number of protons in an atoms.
Since, isobars have different number of protons their properties are different.

Answer 2

chemical properties  of elements largely depend on their electronic configuration and as*the isobars of elements have different atomic number and so, also the electronic configuration, therefore, they have different chemicals property.