🔍 Key Concepts

• Meniscus shape differences between water and mercury in a glass tube • Which liquids wet glass and which do not • Standard lab convention for where to read the level of a curved liquid surface

💭 Think About

• Think about whether water curves upward or downward at the glass wall, and why that happens. • Consider how the behavior of adhesive vs. cohesive forces (liquid-to-glass vs. liquid-to-liquid attraction) changes where you should line up your eye to read the scale. • Ask yourself: Do we use the same reference point on the curve for both liquids, or does it change depending on whether the liquid wets the glass?

✅ Before You Answer

• Confirm which liquid (water or mercury) actually wets glass in standard physics/chemistry treatment. • Visualize (or sketch) the shape of the meniscus for water vs. mercury in a narrow tube. • Double-check which part of the meniscus (center vs. top vs. edges) is the conventional point for accurate pressure/height readings.