1. As pure elements: This means the element exists in its uncombined form, without being chemically bonded to other elements. Examples include:

* Native metals: Gold, silver, copper, platinum

* Noble gases: Helium, neon, argon

* Some non-metals: Carbon (as graphite or diamond), sulfur, phosphorus

2. As compounds: This means the element is chemically bonded to other elements in a fixed ratio. These compounds form minerals, rocks, and other substances. Examples include:

* Water (H₂O): Hydrogen and oxygen bonded together

* Salt (NaCl): Sodium and chlorine bonded together

* Quartz (SiO₂): Silicon and oxygen bonded together

It's important to note that even elements that are commonly found as pure elements can also exist in compounds. For example, gold can be found in gold ores like gold sulfide (Au₂S).