Which of these factors make hydrogen fuel cells a better option than burning fossil fuels?
Hydrogen fuel cells have a higher energy efficiency.
Hydrogen fuel cells create less pollution.
Burning fossil fuels relies on outdated devices and technology.
Hydrogen is the most abundant element in the universe.
Hydrogen fuel cells are more expensive than fossil fuels.

What are the similarities of physical and chemical change ?

For each of the following compounds, write the formula then predict whether it would be a strong, weak, or non-electrolyte when placed in di water. for the ionic compounds only, put (s) or (aq) after the forrmula formula strong, weak or non electrolyte? a calcium hydroxide b. silver carbonate c. lead(ii) sulfate d. phosphorus trifluoride e. sodium phosphide f barium sulfate g. strontium acetate h. zinc nitrate

Many ionic compounds and a few highly polar covalent compounds are because they completely ionize in water to create a solution filled with charged ions that can conduct an electric current.