Speaker: David DeBrota
The speaker will focus on structural metal elements like iron, copper, aluminum, magnesium, and tin. He will have samples of metals and metal ores.
David DeBrota has spoken many times at Scientech. He's not a metallurgist, geologist, or gemologist, but would be willing to play one on TV. He reads about and collects mineral and element specimens.
Program: Metals and Minerals
Speaker: David DeBrota, MD, internal medicine and drug development with Eli Lilly, Scientech member and previous speaker
Introduced By: Bill Halsema
Attendance: NESC: 81, Zoom: 20
Guest(s): Erin DeBrota, Kathleen DeBroda, Sharon Swinford, Chi Wah Rudy Yung
Scribe: Benny Ko
Editor: Ed Nitka
Talk’s Zoom recording found at: https://www.scientechclubvideos.org/zoom/06012026.mp4
On the periodic table, 91 elements are classified as metals. Metals have the common property of electrical conductivity. This is due to the "sea-like" arrangement of "electron-sharing" in metals, which allows electron movement and the propagation of an electromagnetic wave.
Among metals, the "noble metals" such as gold, silver, copper, and platinum occur in pure forms, and they are less reactive. Other metals exist as various compounds in ores and are generally recognized as minerals. Metals can then be extracted from minerals. Alloys are metals mixed with other metals or substances. Steel is iron plus a small amount of carbon. Bronze is copper plus tin, etc.
Besides electrical conduction, metals also conduct heat, e.g., silver and copper are excellent conductors of both heat and electricity. Metallic conductivity increases when its temperature is lowered (resistance drops). At extremely low temperatures, some metals become superconductors.
Minerals are substances that metals form with non-metallic elements such as oxygen, sulfur, silicon, and chlorine. Some common molecules thus formed are the oxides, silicates, chlorides, and sulfides.
Metal Organic Frameworks (MOFs) is a novel class of products created by combining metals with organic compounds known as organic linkers. MOFs can have enormous inner surface areas. Such materials can be used to capture and release gases, e.g., CO2, also for filtration and catalysis.
Metals, when heated or excited, emit a characteristic color unique to that specific metal. Minerals, when heated, can also emit color. Depending on the trace impurities or defects they contain, they can affect the color emitted; hence a host of colors can be produced, as are seen in fireworks.
Some unique properties of metals, in addition to heat and electrical conductivity, include: ductility, malleability, and plasticity. Some metals, such as nickel, can combine with hydrogen to form hydrides that can be used in rechargeable batteries to store energy. Palladium can absorb hydrogen, potentially useful for future hydrogen-powered vehicles. Metallic halides can produce bright light when heated and have historically been used in light bulbs. However, it has largely been replaced by LEDs.
The elements most abundant in the universe are hydrogen and helium. Then how were metallic elements formed? Some lower atomic number metals are formed through nuclear fusion in stars. Some heavier metals are formed when neutrons are captured by the nuclei of lighter elements, resulting in nuclear instability and transformation by beta decay to heavier elements with higher atomic numbers.
Metals are also essential to life. Many body parts are built of metallic elements, such as bones from calcium and magnesium. Metalloenzymes are enzymes containing metallic ion (s); they also have a vital role in various physiological reactions.
Minerals and metals consist of repeating atomic units (unit cells), and these units in turn form metal crystals. The growth of metallic crystals can have industrial applications.
In summary, the practical applications and technologies associated with metallurgy include:
smelting, shaping, surface modification, alloy design, energy storage, hydrogen storage, lighting, and various other industrial uses.
*Dr. DeBrota brought rods of different metals as well as samples of minerals and crystals for display and to share with a captivated audience.
David DeBrota
