Associate Safety Professional Practice Exam

Why does a lead oxide particle settle faster than a silica particle?

1. Size

2. Shape

3. Density

4. Color

The correct answer is: Density

A lead oxide particle settles faster than a silica particle primarily due to its density. Density plays a critical role in the settling behavior of particles in a fluid. The relationship between density and gravitational force determines how quickly a particle will sink or settle in a medium, such as air or water. Lead oxide has a significantly higher density compared to silica. This means that, for the same volume, lead oxide particles weigh more than silica particles. Consequently, when placed in a fluid, the gravitational forces acting on the heavier lead oxide particles will cause them to overcome the buoyant forces more swiftly than those acting on the lighter silica particles. As a result, the lead oxide particles experience a greater net downward force, allowing them to settle faster in comparison to silica particles. Thus, the correct answer emphasizes the importance of density in this context, highlighting why lead oxide would settle more quickly than silica in a given fluid environment.