Polonium doesn't contain another element.
Polonium doesn't contain another element.
The chemistry of polonium is not known in details but I suppose that this element is oxygen.
Oxygen, hydrogen, halogens
Very probable this element is oxygen.
Oxygen, hydrogen, halogens
no, it is most commonly found as a compound
hydrogen is most commonly found as a part of water with oxygen.
neon
In the Earth's atmosphere.
I think it is hydrogen
Because it's the most simple.
Roentgenium is an artificial chemical element.