Metal Winner

How much of our universe is guided by fundamental, unchanging principles of nature, and how much is susceptible to human tinkering? This is a big question is science, and our best guess for an answer is constantly changing. For example,  Alchemists were (in)famous for their quest to turn “base metal” into precious substances, like gold. Eventually, it was discovered that the number of protons on a atom determined what element is would be – meaning that no physical or even chemical reaction can change one element into another. So bad news for would be get rich quick schemes. Even later, however, we found that it IS possible to “transmute” elements in nuclear reactions, although making gold this way is way more expensive than just buying it on QVC or something. 

We now have developed a model of the world in which the properties of elements are determined by the configuration of the electrons in each atom. The implication being, that the attributes of materials were basically set by nature, and there was not much we can do to change it. There is some wiggle room, in the sense that the same element can be made into different atomic configurations (allotropes). An example is graphite and diamond, which are both made of carbon, but only graphite is a good electrical conductor. Also, conductive polymers are organic molecules that surprisingly, can switch between electrical conductors or insulators depending on their chemical state.

Having just read “Stuff Matters” and “The Disappearing Spoon” over the summer, I was kind of in material science mood. There  is a big swath of transition metals on the periodic table. These have similar properties because of the way new electrons add to the orbital shells. In general, the word “metal” means something different to a chemist or physicist than to someone using in the vernacular. Metals are electrical conductors and generally shiny. Both properties result from the configuration of electrons, and available empty states for electrons to move into. 

Modern electronics is based on transistors that are made by doping pure silicon (an insulator) with just a sprinkling of arsenic or geranium atoms, creating a semiconductor. By controlling the amount of dopant atoms, just the right properties can be obtained.

Sometimes, a brute force method also works to force a big change in the properties of a material. Recently. scientists have been able to take quartz, which is about as strong an electrical insulator you will ever find, and make it a conductor – albeit for a very short period of time – by blasting it with a laser.

Here is a quote:

“The laser pulse is an extremely strong electric field, which has the power to dramatically change the electronic states in the quartz,” Georg Wachter, theoretical physicist at the Vienna University of Technology said. “The pulse can not only transfer energy to the electrons, it completely distorts the whole structure of possible electron states in the material.”

 

 

 

Scientists at the Vienna University of Technology have been able to change the properties of quartz glass into metal for very brief moments using laser pulses. Image by Vienna University of Technology

So even the property of being a metal is not set in stone.

 

 

 

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Author: lnemzer

Assistant Professor Nova Southeastern University

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