Assessment and Qualifications Alliance (AQA) GCSE Physics Practice Exam 2025 - Free Physics Practice Questions and Study Guide

The term that describes the curved upper surface of a liquid in a column is known as a meniscus. This phenomenon occurs due to the interplay between cohesive forces within the liquid and adhesive forces between the liquid and the surface of the container. For instance, when water is in a glass container, the adhesive forces between the water molecules and the glass cause the water to climb slightly up the sides of the container, creating a concave shape.

This characteristic of liquids is critical in various scientific and practical applications, such as reading the volume of liquid in a graduated cylinder accurately, where it is important to measure the bottom of the meniscus for precision. Each of the other terms listed refers to different concepts: a solvent is a substance that dissolves a solute, filtration is a process used to separate solids from liquids or gases using a filter, and surface tension is the property that allows the surface of a liquid to behave like a stretched elastic membrane. While related to the behavior of liquids, these terms do not specifically describe the curved surface created at the top of a liquid column.