several, mostly:
Helium is itself a chemical element and therefore is not found in any other chemical element.
In the case of each chemical element the name is found.
carbon, hydrogen, and oxygen
Thid chemical element is carbon (C).
Californium is an artificial chemical element.
Hassium is an artificial chemical element.
Dubnium is an artificial chemical element.
Californium is an artificial chemical element !
Hassium is an artificial chemical element.
Bohrium is an artificial chemical element.
Copernicium is an artificial chemical element.
No, but it is an element found in many minerals.