I believe the third choice is correct.
This can be proven by the fact that to find the molar mass of a compound, you simply add the molar masses of all the atoms within the compound
Hope this helps
A red super giant hope that helps
Answer:
Spanish I dont know spanish.
Explanation:
Your reaction
.. Fe + O2 ---> FexOy
for this reaction..
.. the Fe on the left is in the 0 oxidation state
.. the Fe on the right is in the +(2y/x) oxidation state
.. the O on the left is in the 0 oxidation state
.. the O on the right is in the -2 oxidation state
meaning
.. the O is reduced... . . (it's reduced in oxidation state)
.. the Fe is oxidized.. . .(oxidation state increased)
this is a REDOX reaction
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AND.. it's also a synthesis reaction.. (aka combination reaction)