Q: Substances may be either elements or what?


Read this paragraph and choose the correct option from the provided answers:

Substances may be either elements or pure compounds. They may also be solid, liquid, or gas. Some of the elements (such as silver) exist in the solid form. Other elements (mercury) exist as liquids at room temperature. Elements such as helium and radon exist as gases at room temperature. A compound such as water will take the form of a solid, a liquid, or a gas, depending upon the temperature.

 Choices:

- fundamental compounds

- pure chemicals

- existent compounds

- pure compounds


A:
pure compounds