Question Video: Defining Contamination Science • Third Year of Preparatory School

Video Transcript

Which of the following most correctly describes what is meant by contamination? (A) The mixing of a substance with other substances. (B) Chemical changes in a substance. (C) Changes to the nuclei of atoms in a substance.

To understand contamination, we need to know that more than one substance must be involved. If we have some substance — say, a cloud of gas — nothing that happens in this cloud by itself can contaminate the gas. Contamination requires that some other substance — say, another gas cloud — moves in and mixes with this one. That is, it’s only by mixing substances that contamination can happen. We choose answer option (A). Note, by the way, that this contamination may be radioactive contamination or not. Here, we’re speaking generally about contamination and what it means. It’s the mixing of a substance with one or more other substances.