Final answer:
c) Negative ions. The purifier ingredient typically associated with an activated charcoal air purifier is negative ions, which result from an adsorption process that traps contaminants in the air.
Step-by-step explanation:
The purifier ingredient in an activated charcoal air purifier may be: a) Activated oxygen b) UV light c) Negative ions d) Positive ions. The correct answer is c) Negative ions.
Treatment by activated carbon in air purifiers is mostly due to adsorption, where a chemical species is adhered to the surface of a solid.
In this process, contaminants in the air are trapped by the charcoal, effectively cleaning the air. Although both UV light and negative ions can be used for purifying air, they are not typically associated with activated charcoal purifiers.
UV light, for example, is used to kill bacteria and viruses, and while activated oxygen (ozone) and positive ions can also have purifying effects, these are not the primary functions of activated charcoal.