Dirt WPR 1 Practice Test

The correct answer is hygroscopic. Hygroscopic particles have the ability to absorb moisture from the surrounding environment, which means they can attract and hold water molecules. This property is particularly important in various applications, such as storage and handling of materials, where moisture control is essential.

For example, substances like sugar and salt are hygroscopic; they can take in water vapor from the air, which can lead to clumping or changes in their physical properties. This characteristic is valuable in industries such as pharmaceuticals, food processing, and agriculture, where moisture can significantly impact product quality and effectiveness.

In contrast, hydrophobic particles repel water, meaning they do not absorb moisture. Insoluble particles do not dissolve in water, which is a different characteristic that does not relate to water absorption. Non-polar substances are generally not attracted to polar molecules like water, hence they do not absorb moisture either. Therefore, the distinguishing property of hygroscopic materials makes it the appropriate choice in this context.