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. When diluting a substance, such as a chemical or toxin, it is mixed with a solvent or another material, which reduces its concentration and, consequently, its potential harmful effects. This approach is often used in various fields, including chemistry, medicine, and environmental science, to ensure safety in handling and exposure to potentially dangerous materials.

The other options do not accurately describe this process. Dilating refers to the act of making something wider, larger, or more open but does not involve reducing toxicity or potency. Disinfecting is a process aimed at removing or killing pathogens to reduce their numbers but does not necessarily involve dilution in terms of making a substance less potent. Defoliating relates to the removal of leaves from plants and does not apply to the concept of reducing the harmfulness of a substance.