Magnesium is a silvery-grey metal. When heated in air it reacts with oxygen, burning with a bright flame to form a white powder called magnesium oxide. From the paragraph, identify: ONE compound and one mixture​

Answer: - you don't have to pull very much to lift the mass

Work is the answer 

The challenge that scientists will face with this task is the production of hydrogen since hydrolysis or the decomposition of water (h2o) requires a certain amount of energy to be supplied. scientists should look at how much is this energy supplied. it can be more than what would be produced from the fuel cells which will eventually result to a loss.