There are many elements that do not exist in nature in pure form, especially the highly reactive ones toward either end of the Periodic Table, such as sodium and chlorine. These are always derived from compounds.
Also the only metal that is found in its pure form in nature is gold due to its extreme unreactivity.
Your question hints at something but is incomplete.
iron
Compounds do not form elements. Elements form compounds.
Beryllium can form binary compounds with the majority of the nonmetals and metalloids.
transition metals
All elements and all compounds do not exist as molecules. As examples, noble gases exist as individulal atoms and ionic compounds form lattices.
There is no such thing as a compound element. Something cannot be both an element and a compound Neon is an element and so is made of nothing but neon. Neon does not form any compounds.
Sodium lithium magnesium boron aluminum etal
silver
Aluminum is an element, composed of molecules, is on the periodic chart, does exist by itself AND can be combined to form compounds.
Compounds do not form elements. Elements form compounds.
Probably in ionic compounds where they act as anions. I don't think OBr2 will exist everywhere at all.
maybe an element and some other stuff but no 2 compounds can combine to form just an element
No, it is an element but as such can form compounds.
Yes, they can.
Neither, it is an ion that cannot exist on its own as a substance. It is known as the fulminate ion. It combines with positive ions to form various compounds.
why helium does not react with other elements to form compounds
Beryllium can form binary compounds with the majority of the nonmetals and metalloids.
No. Many compounds are liquids (water, hexane) and gasses (carbon dioxide, ammonia) at room temperature. Many compounds are solid at room temperature and can, but often do not exist in the form of a powder.