What is the attraction between individual water molecules called?

Hydrogen gas has a low or high energy density

Global production of hydrogen from electrolysis accounts for what percent of the total?

What is the approximate current efficiency of fuel cells?

What is the name of hydrogen produced from gas with carbon capture and storage?

What is the name of the epoch when electrons and protons first became bound to form hydrogen atoms?

Hydrogen bond

Covalent bond

What is the approximate atomic mass of hydrogen?

What is the name for a substance that produces an electrically conducting solution when dissolved in a polar solvent?

What are the 4 most abundant elements by mass in the universe in descending order?