What term refers to the negative impact of substances on living organisms?

The term that refers to the negative impact of substances on living organisms is "toxic." When a substance is classified as toxic, it means that it has the potential to cause harm or adverse effects on health when it enters the body or comes into contact with living organisms. This can include a wide range of effects, such as cellular damage, disruption of physiological functions, or even death, depending on the level of exposure and the nature of the substance.

Substances that are considered toxic can be naturally occurring, such as certain plants and fungi that produce toxins to defend themselves, or man-made chemicals that can result from industrial processes. The understanding of toxicity is critical in various fields, including medicine, environmental science, and nanotechnology, where the health implications of nanoparticles and other new materials are scrutinized.

The other terms presented—beneficial, neutral, and inert—convey different meanings. "Beneficial" refers to substances that have positive effects, "neutral" suggests no significant effect, and "inert" indicates substances that do not react chemically. In contrast to these terms, "toxic" specifically highlights the harmful consequences that certain substances can have on living organisms.