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.
United States coins are made out of a few different types of metals. Pennies (1-cent coins) are made of copper and zinc. The zinc is actually on the inside, so we only see the copper color on the outside! A nickel (5-cent coin) is made out of copper and another metal that is called nickel. That should be pretty easy to remember! Dimes (10-cent coins), quarters (25-cent coins) and half dollars (50-cent coins) are made of three really thin sheets of metal that get pressed together. The outside layers of metal are copper and nickel.