Question

Consider the following statements.
I. Repulsive forces are significant when the molecules are close together on average.
II. Attractive intermolecular forces are important when the molecules are fairly close together but not necessarily touching.
III. Attractive forces are ineffective when the molecules arc for apart.
Select correct statements.

• A. I, II and III
• B. I and III
• C. II and III
• D. I and II

Answer 1

Answer: (A)

I, II and III

All of the following statements are correct.

I. Repulsive forces are significant when the molecules are close together on average.
They are short range interactions even on a scale measured on molecular diameter.

These forces are significant only when the molecules are almost in contact.
II. Attractive inter molecular forces are important when the molecules are fairly close together but not necessarily touching. This corresponds to intermediate separations.
They have fairly long range and are effective over several molecular diameters.

III. Attractive forces are ineffective when the molecules arc for apart.