Question

which statement about van der waals forces is true? when the forces are weaker, a substance will have higher volatility. when the forces are stronger, a substance will have lower viscosity. when the forces are weaker, the boiling point of a substance will be higher. when the forces are stronger, the melting point of a substance will be lower.

Explanation:

Van der Waals forces are intermolecular forces. Stronger van der Waals forces require more energy to overcome, leading to higher boiling and melting points. Weaker van der Waals forces mean less energy is needed for molecules to escape, resulting in higher volatility. Viscosity is also related to intermolecular forces, with stronger forces generally increasing viscosity.

Answer:

When the forces are weaker, a substance will have higher volatility.
When the forces are stronger, the boiling point of a substance will be higher.