Sulfur
In the atmosphere.
atom is the smallest part of element
Volcanoes do not emit radiation as a primary feature of their activity. The main substances released by volcanoes are gases, ash, and lava. However, some volcanoes can emit low levels of radon gas, which is a radioactive element that occurs naturally in the Earth's crust.
The smallest part of an element that occurs naturally is an atom. Atoms are the basic units of matter and contain protons, neutrons, and electrons.
Corundum occurs naturally in the form of ruby and sapphire. It is a precious element and has been mined around the world to be made into jewelry and ornamental pieces.
Radon
No, Bromine is not a synthetic element, it occurs naturally
Copper occurs naturally as both an element and in various compounds. In its pure form, copper is an element on the periodic table with the symbol Cu. However, it can also be found in nature as compounds such as copper oxide and copper sulfide.
Iron is an element and occurs naturally in the universe. It is not made.
No. Sulfur is a natural element. It even occurs naturally as a native element near volcanic vents.
Radioactive Decay occurs naturally all around us. If you test for radiation with a Geiger Counter, you will find that it picks up radiation in the air around you. Mostly, however, radioactive decay occurs in the earth's crust. I cannot name a specific element, as there are many that decay.
The lightest naturally occurring actinide on Earth is thorium, which has the atomic number 90. It is a naturally occurring radioactive element found in small amounts in soil and rocks.