Question

CHEMISTRY QUESTION

You have three elements, A, B, and C, with the following electronegativity values:

A = 0.75
B = 3.2
C = 3.7

You react the elements to form the substances AB, AC, and BC. Answer the following questions:

• Which substances will form an ionic bond?
• Which substances will form a covalent bond?
• Is any of the substances are ionic compounds, which element is the cation and which is the anion? Explain your answer.

Answer 1

Electronegativity of an element refers to its tendency to attract a pair of electrons towards itself.

An ionic bond is formed by the complete transfer of electrons from one element to the other. This implies that the combining elements should exhibit a large difference in their electronegativity values.

In contrast, a covalent bond is formed by a mutual sharing of electrons between 2 atoms that do not differ much in their electronegativity values.

Given Electronegativity values are:

A = 0.75

B = 3.2

C = 3.7

a) The difference in electronegativity is the greatest between A and C i.e. 3.7 - 0.75 = 2.95. Hence, AC will form an ionic bond

b) The difference is least between B and C i.e. 3.7 -3.2 = 0.5. Hence, BC will form a covalent bond

c) In AC, C is more electronegative than A

C = anion and A = cation