This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Rn. d. Most elements tend to gain or lose electrons ‘ions’ e. The number of protons defines the elements. ~ The number of neutrons defines the isotope, a.k.a. the ‘element version’. ~ There are only a small number of stable isotopes. All others are either unstable or radioactive. f. Bonds ~ How atoms are held together to make crystals, then minerals. ~ Ionic: Electron donation and acceptance ~ Covalent: Sharing of bonds ~ Def (From earlier) B. Polymorphs 1. Two minerals differing only by crystal structure. a. Carbon: graphite or diamond b. SiO 2 : common quartz, 5 others 2. Composition a. 3500-4000 minerals ~ 90 elements and 230 structures * 20 minerals = 95% of crust C. Silicate Minerals 1. Need abundant elements/opposite charges. a. Si +4 and O +2...
View Full Document
- Spring '08
- Atom, Chemical element, SiO2, Minerals A. Building, C. Silicate Minerals, Tectonics A. Reasons