<span>The correct answer is b. Radon. Oxygen, Hyrdrogen, and Boron, are not radioactivel ike Radon and it regenerates quickly meaning that even though it has a short half-life period, it stays for a long time once released. It also has no taste so it's difficult to notice without proper gear because you can't feel it.</span>
It's A, metals. Metals are solid at room temperature but still very malleable and the best conductors. Metalloids can still conduct electricity but nowhere near as well as metals.
It would be D.the food chain
Argon is a pure element which means that it cannot be broken down further than it already is. Methane, however, is a hydrocarbon, which means it is made out of both hydrogen and carbon and thus can be broken down to separate those elements.
