Which of the following processes involves making a substance less harmful or potent by adding another substance?

The process of making a substance less harmful or potent by adding another substance is known as diluting. This involves reducing the concentration of a harmful or potent chemical by mixing it with a less concentrated solution or a neutral substance, effectively lowering its potential dangers. For example, if a strong acid is diluted with water, its strength and corrosive effects are significantly reduced, making it safer to handle.

In contrast, dilating typically refers to the process of making something larger or wider, such as when blood vessels expand to increase blood flow. Disinfecting involves using chemicals to kill pathogens and disinfect surfaces, which does not inherently lessen the harmfulness of a substance by dilution but rather aims to eliminate harmful organisms. Defoliating refers to the removal of leaves from a plant, often for agricultural purposes, and is unrelated to altering the potency of a substance.