How should liquid be measured in a graduated cylinder?

Measuring liquid in a graduated cylinder requires precision to ensure accurate readings. The correct method is to read the measurement at the lowest point of the meniscus, which is the curve formed at the surface of the liquid due to surface tension. This is important because the meniscus can create a visual distortion in reading the liquid level.

When you measure at the lowest point of the meniscus, you eliminate discrepancies that could arise from parallax error or misinterpretation of the liquid level. This method provides a consistent point of reference across various measurements, ensuring that the liquid level is read correctly.

Inaccuracies can occur if you measure at the top of the meniscus or at other inappropriate points, as these could lead to inflated or deflated liquid readings. Using a ruler is not applicable for this scenario, as the graduated cylinder is designed with marked increments for direct reading, and the midpoint of the cylinder does not correspond to the liquid's actual volume. Thus, measuring at the lowest point of the meniscus is the most reliable and standardized method, ensuring that measurements are both accurate and repeatable.