Astronomers use chemical signatures to determine<span> the age and .... </span>Gas<span> mixtures that contain more than </span>4<span>% hydrogen in </span>air<span> are potentially explosive. ... water vapor, </span>carbon dioxide<span>, and several other </span><span>gases</span>
The answer to this is to prevent dilution of the base, which may affect the results. I think that is right.
As the period number increases on the periodic table, moving from top to bottom, the atomic radius of the elements increases as well.
