Final answer:
Weighing paper should be used to weigh out small quantities because it allows for easy transfer and minimizes the additional mass on the scale. It's commonly used for precise measurements that need to be transferred, while weigh boats are better for larger amounts.
Step-by-step explanation:
The correct answer to the question "When should weighing paper be used, as opposed to a weigh boat?" is D. Weighing paper should be used to weigh out small quantities.
Weighing paper is ideal for small quantities because it is thin and allows for easy transfer of a substance without spilling. It also minimizes the mass added to the scale by the container. Accurately determining the mass of a chemical often involves the use of weighing paper, especially when dealing with small, precise measurements that need to be transferred into another container such as a volumetric flask or a reaction vessel.
In contrast, weigh boats are better suited for larger quantities that may not be as easily transferred or are too large for the minimal surface area of weighing paper. A weigh boat also provides more support and containment for solid or powdered materials.