Answer:
molarity = moles of solute / liter of solution
Explanation:
I'm not sure what type of fuel you're talking about. If you mean fossil fuel then kerosene has the highest density of all of the things you listed.
Carbon can form four covalent bonds.
Hydrogen can form one covalent bond.
Nitrogen can form three covalent bonds.
Oxygen can form two covalent bonds.
Answer is A. The reason to create such is to conduct electricity, and metal conducts electricity.
Hope this helps, Tiara