Related Experiment Video
Updated: Jul 12, 2026
11:50
Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
Noble gas partitioning between metal and silicate under high pressures
Science (New York, N.Y.)
|February 5, 1993
Summary
Noble gases like helium and argon show very low partitioning into iron melts under high pressure. This suggests Earth
Area of Science:
- Geochemistry
- Planetary Science
- High-Pressure Mineral Physics
Background:
- Noble gases are important tracers for understanding planetary formation and evolution.
- The partitioning behavior of elements between different melts provides insights into core formation processes.
Purpose of the Study:
- To quantify the partitioning of noble gases (He, Ne, Ar, Kr, Xe) between silicate and iron melts.
- To assess the implications of noble gas partitioning for the composition of Earth's core.
Main Methods:
- Experimental measurements of noble gas partitioning.
- Experiments conducted under high pressures (up to 100 kilobars).
- Analysis of noble gas concentrations in coexisting silicate and iron melts.
Main Results:
- Noble gas partition coefficients between silicate and iron melts are significantly less than unity.
- Partition coefficients systematically decrease with increasing pressure.
- Helium, neon, argon, krypton, and xenon all exhibit this behavior.
Conclusions:
- Under equilibrium conditions, Earth's core would contain only negligible amounts of noble gases.
- The partitioning behavior suggests noble gases are largely excluded from the metallic core during planetary differentiation.
Related Concept Videos
02:54Noble Gases
The elements in group 18 are noble gases (helium, neon, argon, krypton, xenon, and radon). They earned the name “noble” because they were assumed to be nonreactive since they have filled valence shells. In 1962, Dr. Neil Bartlett at the University of British Columbia proved this assumption to be false.
02:32Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
02:37Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:48Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
03:03Mixtures of Gases: Dalton's Law of Partial Pressures and Mole Fractions
Unless individual gases chemically react with each other, the individual gases in a mixture of gases do not affect each other’s pressure. Each gas in a mixture exerts the same pressure that it would exert if it were present alone in the container. The pressure exerted by each individual gas in a mixture is called its partial pressure.
02:37Types of Chemical Bonds
Chemical bonding theories were pioneered by American chemist Gilbert N. Lewis. He developed a model called the Lewis model to explain the type and formation of different bonds. Chemical bonding is central to chemistry; it explains how atoms or ions bond together to form molecules. It explains why some bonds are strong and others are weak, or why one carbon bonds with two oxygens and not three; why water is H2O and not H4O.