Here's why:

* Elements are the simplest pure substances that cannot be broken down further by chemical means. They are found on the periodic table.

* Compounds are formed when two or more different elements chemically combine in a fixed ratio.

* Mixtures are combinations of substances that are not chemically bonded and can be separated by physical means.

Tungsten is a pure substance found on the periodic table, meaning it is a single type of atom and cannot be broken down into simpler substances.