History of Carbon-12
- Before 1959, IUPAP and IUPAC used oxygen to define the mole.
- In 1959-60, the two organizations agreed to define the mole as the number of atoms in 12 grams of carbon-12.
- The definition of the mole was adopted by the CIPM in 1967 and by the 14th CGPM in 1971.
- In 1961, carbon-12 was selected as the standard relative to which the atomic weights of all other elements are measured.
- In 1980, the CIPM clarified that the carbon-12 atoms are unbound and in their ground state.
Hoyle State of Carbon-12
- The Hoyle state is an excited, spinless, resonant state of carbon-12.
- It was predicted to exist by Fred Hoyle in 1954.
- The existence of the Hoyle state is essential for the nucleosynthesis of carbon in helium-burning stars.
- The Hoyle state is populated when a helium-4 nucleus fuses with a beryllium-8 nucleus in a high-temperature environment.
- The Hoyle state primarily decays back into its three constituent alpha particles.
Isotopic Purification of Carbon-12
- Isotopes of carbon can be separated in the form of carbon dioxide gas.
- This can be done through cascaded chemical exchange reactions with amine carbamate.
- Isotopic purification is important for various applications, such as scientific research and medical diagnostics.
- It allows for the study of specific isotopes and their properties.
- Isotopically pure carbon can also be used in the production of materials like diamond.
Related Concepts
- Avogadro constant
- Carbon-11
- Carbon-13
- Carbon-14
- Isotopes of carbon
References
- Table of Isotopic Masses and Natural Abundances (PDF). 1999.
- Atomic Weights and the International Committee — A Historical Review. 2004-01-26.
- Hoyle, F. (1954). On Nuclear Reactions Occurring in Very Hot Stars.
- Freer, M.; Fynbo, H. O. U. (2014). The Hoyle state in C.
- Alshahrani, B.; Kibédi, T.; Stuchberry, A. E.; Williams, E.; Fares, S. (2013). Measurement of the radiative branching ratio for the Hoyle state using cascade gamma decays.
Carbon-12 Data Sources
| Reference | URL |
|---|---|
| Glossary | https://harryandcojewellery.com.au/blogs/glossary/carbon-12 |
| Wikipedia | http://en.wikipedia.org/wiki/Carbon-12 |
| Wikidata | https://www.wikidata.org/wiki/Q1058364 |
| Knowledge Graph | https://www.google.com/search?kgmid=/m/03ns4_ |