Answer:
40.3 for the unit that represents the minimum amount of magnesium oxide I beilieve.
Step-by-step explanation:
Magnesium atoms are heavier than oxygen atoms, so we expect more than 50% of magnesium in the weight composition. Taking just one atom of Mg and one atom of O you will get a mass of 16.0 + 24.3 = 40.3.
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