Hey you is a colorless, odorless gas that forms when fuels are not completely burned. carbon monoxide carbon dioxide radon hydrogen

Radon hope this helps.
 
original answer was monoxide which is incorrect and dioxide is incorrect and it is not hydrogen meaning it has to be radon.

False because saturated fatty acids contain only single bond

So the main goal for the elements is stability which is a complete/full valence shell and typically the magic number for a stable element is 8 valence electron but not always. so elements to the left of the periodic table tend to be way less stable then those on the right, so the elements on the left are much more reactive.