Currently, most hydrogen is made this way from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen. This process is known as electrolysis. Some algae and bacteria, using sunlight as their energy source, even give off hydrogen under certain conditions.
Originally, metal roofs were made of corrugated galvanized steel: a wrought ironâsteel sheet was coated with zinc and then roll-formed into corrugated sheets. Another approach is to blend zinc, aluminum, and silicon-coated steel.
A paper clip is usually made of mild steel or plastic. There are some other metals used, but they are much less common. The steel ones are plated or have a vinyl coating.  â¦ A history of this handy office product is posted at Wikipedia, and a link is provided.