unreacted

Imagine mixing baking soda and vinegar—usually, they react with fizzing excitement! But if the two aren't mixed thoroughly, some of the baking soda stays *unreacted*, meaning it hasn't changed or joined with the vinegar yet.

"Unreacted" describes a substance that has not gone through a chemical change even though it was part of a reaction or process. It is most common in chemistry when talking about material left over after a reaction has finished. In simple terms, it means the substance is still there in its original form instead of turning into something new. For example: "The scientist analyzed the amount of unreacted material left at the bottom of the beaker."

"Unreacted" is mainly a scientific word. It describes a substance that was present during a chemical reaction but did not itself change into a new substance. In other words, it stayed in its original form instead of being used up. This idea is common in chemistry, industry, and materials science, where people measure how much starting material remains after a process. For example: "The unreacted chlorine gas posed a significant safety hazard to the laboratory staff."

You will often see the word next to nouns such as "material," "chemical," "gas," "acid," or "monomer." In each case, the meaning is similar: the substance was there, but some of it did not react. That can matter for safety, waste, product quality, or lab results. A report might mention unreacted fuel in an engine, unreacted resin in a mixture, or unreacted particles in a sample.

The word is not usually used for people's feelings or behavior in everyday English. For a person, English normally uses words like "calm," "silent," "unmoved," or "unresponsive" instead. So the clearest way to understand "unreacted" is as a technical word for something, usually a chemical substance, that remains unchanged after a reaction or process.