How does viscosity change as temperature is raised? (a) viscosity of a gas increases (b) viscosity of a gas decreases (c) viscosity of a liquid decreases (d) viscosity of a liquid increases Choose the correct combination.

a and c are true
b and c are true
b and d are true
a and d are true

Correct answer: a and c are true

Solution

Heating a gas speeds up molecules so momentum transport across layers increases, raising viscosity. Heating a liquid weakens cohesive forces, lowering viscosity.

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