Answer:
55.4g
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Explanation:
Given parameters:
Number of atoms in the bottle = 8.34 x 10²²atoms
Unknown:
Mass of air in the bottle  = ?
Solution:
The given specie is argon.
 Molecular mass of Argon  = 40g/mol
To find the mass of this Argon ;
     Mass  = number of moles x molecular mass;
 Let us find the number of moles of the Argon;
       6.02 x 10²³ atoms can be found in 1 mole of any substance
       8.34 x 10²² atoms will give [tex]\frac{8.34 x 10^{22} }{6.02 x 10^{23} }[/tex]  mole of Argon
                            = 0.139mole of Argon
So;
    Mass of argon  = 40g/mol x 0.139mole  = 55.4g
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