Monday, March 11, 2019

TURNING LEAD INTO GOLD - Before chemistry was a science, there was alchemy. One of the supreme quests of alchemy was to transmute (transform) lead into gold. Lead (atomic number 82) and gold (atomic number 79) are defined as elements by the number of protons they possess. Changing the element requires changing the atomic (proton) number. The number of protons cannot be altered by any chemical means. However, physics may be used to add or remove protons and thereby change one element into another. Because lead is stable, forcing it to release three protons requires a vast input of energy, such that the cost of transmuting it greatly surpasses the value of the resulting gold.

A tiny bowl of gold nuggets
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Turning Lead Into Gold
How to Turn Lead Into Gold
by Anne Marie Helmenstine, Ph.D. 

Before chemistry was a science, there was alchemy. One of the supreme quests of alchemy was to transmute (transform) lead into gold.
Lead (atomic number 82) and gold (atomic number 79) are defined as elements by the number of protons they possess.
Changing the element requires changing the atomic (proton) number. The number of protons cannot be altered by any chemical means.
However, physics may be used to add or remove protons and thereby change one element into another.
Because lead is stable, forcing it to release three protons requires a vast input of energy, such that the cost of transmuting it greatly surpasses the value of the resulting gold.
History
Transmutation of lead into gold isn't just theoretically possible; it has been achieved!
There are reports that Glenn Seaborg, 1951 Nobel Laureate in Chemistry, succeeded in transmuting a minute quantity of lead (possibly en route from bismuth, in 1980) into gold.
There is an earlier report (1972) in which Soviet physicists at a nuclear research facility near Lake Baikal in Siberia accidentally discovered a reaction for turning lead into gold when they found the lead shielding of an experimental reactor had changed to gold.
Transmutation Today
Today particle accelerators routinely transmute elements. A charged particle is accelerated using electrical and magnetic fields.
In a linear accelerator, the charged particles drift through a series of charged tubes separated by gaps.
Every time the particle emerges between gaps, it is accelerated by the potential difference between adjacent segments.
In a circular accelerator, magnetic fields accelerate particles moving in circular paths.
In either case, the accelerated particle impacts a target material, potentially knocking free protons or neutrons and making a new element or isotope.
Nuclear reactors also may be used for creating elements, although the conditions are less controlled.
In nature, new elements are created by adding protons and neutrons to hydrogen atoms within the nucleus of a star, producing increasingly heavier elements, up to iron (atomic number 26).
This process is called nucleosynthesis. Elements heavier than iron are formed in the stellar explosion of a supernova.
In a supernova gold may be transformed into lead, but not the other way around.
While it may never be commonplace to transmute lead into gold, it is practical to obtain gold from lead ores.
The minerals galena (lead sulfide, PbS), cerussite (lead carbonate, PbCO3), and anglesite (lead sulfate, PbSO4) often contain zinc, gold, silver, and other metals.
Once the ore has been pulverized, chemical techniques are sufficient to separate the gold from the lead. The result is almost alchemy. 

Anne Marie Helmenstine, Ph.D.
·   Ph.D. in biomedical sciences from the University of Tennessee at Knoxville - Oak Ridge National Laboratory.
·   Science educator with experience teaching chemistry, biology, astronomy, and physics at the high school, college, and graduate levels.
·   ThoughtCo and About Education chemistry expert since 2001.
·   Widely-published graphic artist, responsible for printable periodic tables and other illustrations used in science.
Experience
Anne Helmenstine, Ph.D. has covered chemistry for ThoughtCo and About Education since 2001, and other sciences since 2013. She taught chemistry, biology, astronomy, and physics at the high school, college, and graduate levels. She has worked as a research scientist and also abstracting and indexing diverse scientific literature for the Department of Energy.
In addition to her work as a science writer, Dr. Helmenstine currently serves as a scientific consultant, specializing in problems requiring an interdisciplinary approach. Previously, she worked as a research scientist and college professor. 
Education
Dr. Helmenstine holds a Ph.D. in biomedical sciences from the University of Tennessee at Knoxville and a B.A. in physics and mathematics with a minor in chemistry from Hastings College. In her doctoral work, Dr. Helmenstine developed ultra-sensitive chemical detection and medical diagnostic tests.
Anne Marie Helmenstine, Ph.D.
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A tiny bowl of gold nuggets

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