<span>The hardest known mineral is diamond.
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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
Find the molar mass of CH3 and divide that by 45.0. That should give a whole number and then mult that whole number by CH3 to find molecular formula to get like ( incorrect ex: C2H6) which is mult by 2
The removal of trees would most likely decrease the amount of carbon in the atmosphere.
Please note that it is useful to add the options provided with the question, in order to get a most accurate answer and have your question answered quicker.
Hope this helps!!