Final answer:
The term 'opaque' refers to materials through which light cannot pass, such as metals, and it is the correct option among the given choices of dull, dark, obscure, and opaque. Opaque materials absorb or reflect light, preventing visibility through them.
Step-by-step explanation:
Among the options provided – dull, dark, obscure, and opaque – opaque is the term that specifically refers to materials through which light cannot pass. An opaque object does not allow any transmission of light, thereby making it impossible to see through it. This property is due to the material's internal structure, which absorbs or reflects light, preventing it from passing through. Examples of opaque materials include metals like the iron meteorite mentioned in the reference, which has opacity, and various other substances that do not permit the passage of light. In contrast, terms like dull and dark describe the absence or reduction of light but do not inherently refer to the optical property of transparency or the lack thereof.
Understanding these terms can be applied in various contexts, such as in designing a microscope experiment where an opaque light stop is used to block light and create a darkfield image, or in everyday situations like observing that light does not bend around corners when passing through an open door.