Answer is none of the above
Answer:
If anything but H2O were found, it would be evidence of a chemical change. Therefore, 4 is the only viable evidence that it was a physical change of H2O liquid to H2O gas.
the big number describes the number ratio in a chemical equation
so for example,
2H2 + O2 --> 2H2O means
2 moles of hydrogen reacts with one mole of oxygen to form 2 moles of water
and as you know, the small (subscript) number determines the number of atoms of that element in one molecule of a compound
so I believe that drawing a normal lewis structure ( O=O ) should be correct
Answer:
Cattle produce a lot of methane gas, primarily through enteric fermentation and fermentation of their manure. Methane is a powerful greenhouse gas that, along with nitrous oxide, carbon dioxide, and some other compounds in the atmosphere, create a blanket around our planet.