What is the definition of an abrasive substance?

An abrasive substance is defined as a solid material that is used to wear down or polish surfaces through friction. This definition aligns with how abrasives are commonly utilized in various industrial applications, including blasting operations where they are used to clean or smooth surfaces by eroding material away.

Abrasives can take many forms, such as materials like sand, glass, or gemstones, and their effectiveness comes from their ability to be more resistant than the material they are used on. This characteristic is crucial in operations that require precise surface finishing or material removal.

In contrast, the other options do not meet the criteria of what constitutes an abrasive. Chemicals used for cleaning surfaces may assist in surface maintenance but they rely on chemical reactions rather than physical abrasion. Liquids for cutting materials typically refer to fluids used for lubrication or cooling in cutting processes, instead of solid abrasives. Gases used for welding perform a completely different role, focusing on creating a high-temperature environment for fusing materials, rather than abrasively altering surfaces. Therefore, identifying an abrasive substance as a solid used in blasting operations accurately captures its primary function and distinction in an industrial context.