26. Iron: The strength and low cost of iron make it perfect for engineering applications, and iron compounds serve as an etchant for copper in the manufacture of printed circuit boards (such as the Sunstone PCB collection).
29. Copper is found in almost all electronics, as it is superior to comparative elements—like aluminum—in electricity and heat transfer. For example, take any stick of RAM and look at where it connects to the computer; all of those connections are made of copper.
30. Zinc is used in different types of batteries, such as the zinc-carbon battery (in which zinc is the case for the battery), the nickel-zinc battery (often found in cordless phones or digital cameras), and the zinc-air battery (commonly found in hearing aids, as well as in electrical vehicles).
33. Arsenic: Though not directly related to any tech product because of its toxicity, arsenic is commonly used in bronzing and pyrotechnics.
34. Selenium: The copper indium gallium selenide compound is used in the production of some solar cells, specifically the thin-film category. The Brunton Solaris 52 CIGS Foldable Solar Panel uses selenium (the "CIGS" in its name stands for copper indium gallium selenide).
35. Bromine compounds are used to make the light-sensitive component of photographic emulsion—without bromine compounds, photographs would not capture sufficient light. One such product is Kentmere bromide photo paper.
36. Krypton gas is whitish in color, so krypton-based light bulbs are useful in photography as a brilliant white light source. Krypton is often used in high-speed photography.
40. Zirconium is extremely resistant to heat, so it’s ideal for space vehicles and aircraft. Jet-engine blades are manufactured with zirconium.
41. Niobium: Lithium niobate is used in mobile phone production, incorporated into surface acoustic wave filters that convert acoustic waves into electrical signals and make smartphone touchscreens work. SAW filters also provide cell signal enhancement, and are used to produce the Apple iPad 2.
42. Molybdenum is mainly used in steel production—it has the ability to withstand extremely high temperatures without changing shape. It is a component of armor, aircraft parts, industrial motors, filaments, and electrical contacts.
43. Technetium: Despite its name, technetium is used mainly in the medical industry. It serves as a medical tracer that doctors can detect in the human body with a gamma camera.
44. Ruthenium, when added to compounds, is used to make dye-sensitive solar cells, but those aren't commercially available.
45. Rhodium: Like platinum (78), rhodium is used in catalytic converters for cars, but rhodium is specifically suited for diesel-powered vehicles.
46. Palladium is used to make multilayer ceramic capacitors. These take the form of squares or rectangles mounted on the surface of a printed circuit board; you'll see them on most computer motherboards.
48. Cadmium, used in the production of cadmium telluride photovoltaics, offers a cheap and efficient method of manufacturing solar panels. Though it isn't widely available for commercial use, you can find some places to buy the panels online, including eBay (the term “CdTe” refers to the cadmium telluride compound).