i think methane is found underground and most metals
Antimony is found in the mineral stibnite.
Lava
Oxygen.
The molten material that reaches earth's surface is lava :)
minerals
Kryptonite is not found anywhere at all because it's a fictional material.
Magma
air and rockair and rock
Scientists know the Earth's core is made of a different material because earthquake waves pass through liquids, like the Earth's outer core, differently than they pass through solids.
three
The three different physical states in which water can commemly be found on earth are solid, liquid, and gas.
Diamond is not a metal, it is a mineral: the hardest material on earth.