Question

The iron needle will float on clean water but sink when some detergent is added to this water.

• A. True
• B. False

Answer 1

The correct option is A True

The given statement is true. The iron needle will float on clean water but sink when some detergent is added to this water. Surface active substances such as detergents decrease the surface tension of the liquid. Surface tension of a liquid is a molecular phenomenon of liquids involving the force of cohesion among the liquid molecules.