Book contents
- Frontmatter
- Contents
- Preface to the second edition
- Foreword to the first English edition
- Foreword to the French edition
- Acknowledgments
- Introduction
- 1 The properties of elements
- 2 Mass conservation and elemental fractionation
- 3 Fractionation of stable isotopes
- 4 Geochronology and radiogenic tracers
- 5 Element transport
- 6 Geochemical systems
- 7 The chemistry of natural waters
- 8 Biogeochemistry
- 9 Environments
- 10 Mineral reactions
- 11 The solid Earth
- 12 The Earth in the Solar System
- 13 The element barn
- Appendix A Composition of the major geological units
- Appendix B The mixing equation for ratios
- Appendix C A refresher on thermodynamics
- Appendix D The geological time scale
- Appendix E An overview of analytical methods
- Appendix F Physical and geophysical constants
- Appendix G Some equations relative to residence time
- Appendix H The adiabatic atmosphere
- Further reading
- Index
1 - The properties of elements
Published online by Cambridge University Press: 05 June 2013
- Frontmatter
- Contents
- Preface to the second edition
- Foreword to the first English edition
- Foreword to the French edition
- Acknowledgments
- Introduction
- 1 The properties of elements
- 2 Mass conservation and elemental fractionation
- 3 Fractionation of stable isotopes
- 4 Geochronology and radiogenic tracers
- 5 Element transport
- 6 Geochemical systems
- 7 The chemistry of natural waters
- 8 Biogeochemistry
- 9 Environments
- 10 Mineral reactions
- 11 The solid Earth
- 12 The Earth in the Solar System
- 13 The element barn
- Appendix A Composition of the major geological units
- Appendix B The mixing equation for ratios
- Appendix C A refresher on thermodynamics
- Appendix D The geological time scale
- Appendix E An overview of analytical methods
- Appendix F Physical and geophysical constants
- Appendix G Some equations relative to residence time
- Appendix H The adiabatic atmosphere
- Further reading
- Index
Summary
The 92 naturally occurring chemical elements (90, in fact, because promethium and technetium are no longer found in their natural state on Earth) are composed of a nucleus of subatomic nucleons orbited by negatively charged electrons. Nucleons are positively charged protons and neutral neutrons. As an atom contains equal numbers of protons and electrons with equal but opposite charges, it carries no net electrical charge. The mass of a proton is 1836 times that of an electron. The chemical properties of elements are largely, although not entirely, determined by the way their outermost shells of electrons interact with other elements. Ions are formed when atoms capture surplus electrons to give negatively charged anions or when they shed electrons to give positively charged cations. An atom may form several types of ions. Iron, for example, forms both ferric (Fe3+) ions and ferrous (Fe2+) ions, while it also occurs in the Fe0 elemental form.
A nuclide is an atomic nucleus characterized by the number Z of its protons and the number N of its neutrons regardless of its cloud of electrons. The mass number A is the sum of the nucleons N + Z. Different interactions act in the nucleus and explain its binding: the short-range (nuclear) strong force, the long-range electromagnetic force, and the mysterious intermediate weak force.
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- Information
- GeochemistryAn Introduction, pp. 5 - 24Publisher: Cambridge University PressPrint publication year: 2009