Which property of water causes the curved surface shown in figure 2-1?

The curved surface shown in figure 2-1 is primarily due to the property of water known as surface tension. This phenomenon arises from cohesive forces between water molecules, which create a "skin" at the surface, allowing it to resist external forces. Additionally, adhesive forces between water and the container can also contribute to the curvature, depending on the context. Together, these forces result in the characteristic meniscus shape observed in a liquid's surface.