Respuesta :

Answer:  1 g H2 gas

Explanation:  

8g O2 = 0.25 moles

1g H2 = 0.50 moles [I assume you mean H2, not H.  If it is H, then moles = 1.0 moles H

7g N2 = 0.25 moles

1.5 g He = 0.43 moles

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The moles above are based on molecules.  All but He are multiplied by 2 to give the number of atoms.  If H2 is correct, it has the greatest number of atoms.  (Not if it is just H).