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.
Zinc sheet metal is used to make zinc bars. 64 Zn, the most abundant isotope of zinc, is very susceptible to neutron activation, being transmuted into the highly radioactive 65 Zn, which has a half-life of 244 days and produces intense gamma radiation.