There are 7 digits from decimal to 1st digit, and it's coming from right, so exponent will be in negative 7
In short, Your Answer would be: Option C) <span>6.75 × 10-7
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Hope this helps!
I would say Na. Oxygen has 2 valence electrons and when reacting with other molecules, the ones with the fullest or emptiest shells will react the least. Both H2 and Na are in the Alkali Metals in the first row, but since H2 has 2 molecules, it would use more oxygen than Ana
I think this is what your talking about.