Final answer:
Mercury has the highest surface tension at room temperature, attributed to its metallic bonds. Water, ethanol, and acetone have lower surface tensions due to weaker intermolecular forces.
Step-by-step explanation:
Among the substances listed - water, ethanol, mercury, and acetone - mercury has the highest surface tension at room temperature. Surface tension is a property dependent on the intermolecular forces of a liquid; the stronger the intermolecular forces, the higher the surface tension. In the case of mercury, its exceptionally high surface tension, 4.86 x 10-1 J/m² (at 20°C), is due to the presence of strong metallic or electrostatic bonds. In contrast, water has a high surface tension too, at 7.29 x 10-2 J/m² (at 20°C), owing to its hydrogen bonding, but it is lower compared to mercury's. Ethanol and acetone have much lower surface tensions due to their weaker intermolecular forces compared to water and mercury.