radioaktiivisissa

Radioaktiivisissa is a Finnish inflected form of the adjective radioaktiivinen, meaning "radioactive." It is the inessive plural form, used to express location or context for multiple items or subjects, such as where something is found or occurs. On its own it is not a standalone noun but a form that typically accompanies a following noun or is understood from context.

In technical and scientific Finnish, radioaktiivisissa is commonly used to describe environments, materials, or conditions that involve radioactivity. Examples include phrases like radioaktiivisissa aineissa (in radioactive substances) and radioaktiivisissa olosuhteissa (in radioactive conditions). The form signals that the described items share the radioactive characteristic and are discussed within the same contextual domain, such as safety, measurement, or containment.

Etymology and grammar reflect Finnish morphology: radioaktiivinen is formed from the root radio- (radio, radiation) and -aktiivinen (active), with the suffixes adapting for number and case. The inessive plural suffix -issa indicates “in/inside” for plural references. As a grammatical construction, radioaktiivisissa expects a noun to complete the phrase, and its use is typical in formal language, manuals, and regulatory or scientific texts dealing with radiation, radiological protection, or nuclear materials.

Related terms include radioaktiivisuus (radioactivity), säteily (radiation), and säteilyturvallisuus (radiation safety). The form reflects how Finnish expresses contextual attributes of multiple items in relation to radioactivity.