Explanation:
The answer is to this question is
60 m/s.
Okay so we are given these requirements:
element which can be used to stuff
bottles that enclose ancient paper
must be a gas at room temperature
must be denser than helium
must not react with other elements
The only element that comes into my
mind is:
<span>Argon</span>
The eletron pairs repel each other in a tetrahedral shape.