Most elements in nature are found in a combined form due to their tendency to react with other elements and form compounds. For instance, elements like oxygen and silicon readily combine with other elements to form a variety of compounds, which are more stable than their elemental forms. The reactivity of an element is influenced by its atomic structure, and many elements seek to achieve a full outer shell of electrons, often resulting in combinations with other elements.
Some elements, however, do exist in their elemental form in nature. These are generally elements that are less reactive or have very stable configurations. For instance, noble gases like helium, neon, argon, krypton, xenon, and radon are typically found in their elemental state because they are chemically inert. Similarly, metals like gold, platinum, and silver can also be found in their elemental form, as they are resistant to corrosion and oxidation.