The positions of some elements in the Periodic Table are shown below.
Which one of the following pairs of elements is most likely to form a covalent bond?
A. magnesium and bromine
B. strontium and oxygen
C. potassium and chlorine
D. calcium and chlorine
E. beryllium and iodine
Covalent bonds basically are due to the donation of electron by each atom and subsequently sharing those with each other.
Now in our case we don’t want the electronegativity difference to be too big as to form Ionic bond. Thus we seek lower electronegativity levels. Thus we form the bond between I and Be as I in all given option has the lowest electronegativity and thus the difference won’t be too big to form an ionic bond