What should be done to portions of a composite sample before beginning tests?

Thoroughly remixing portions of a composite sample before conducting tests ensures that the sample is homogenous, allowing for accurate and reliable results. In many analytical procedures, the initial mixing helps distribute various components evenly throughout the sample.

When a composite sample is collected, especially from different locations, there may be variations in material due to sorting or segregation during collection. By remixing, you eliminate these variations and ensure that any tests performed will reflect the true characteristics of the overall sample. This step is crucial for materials that might segregate or settle, as uniformity in the sample directly impacts the validity of the test results.

While other options may suggest alternative actions, they do not achieve the same level of consistency required for accurate testing and analysis. For example, waiting for portions to settle or performing tests immediately could introduce variability that compromises result integrity. Reaggregating without remixing would not ensure that all components are evenly distributed, which is essential for meaningful comparisons and decisions based on test results.