GEL168 Lecture 4: Geology Based Chemistry Minerals
Document Summary
An atom is the smallest particle of an element that retains its physical properties. All atoms, of a certain type of element, have the same number of protons but the number of neutrons they have may vary creating isotopes. Protons and neutrons are found in the nucleus. Electrons circle the nucleus in a cloud made up of various energy levels/shells the first shell wants 2 e- and the next ones want 8 e-. Outer shells frequently don"t have enough e- to fill them so they take or share the e-(e- Bonds - we will consider 3 types - ionic, covalent, metallic. If an atom loses and e- it has a + charge, if it gains an e- it has a - charge. Atoms with a + or a - charge are called ions (cations(+) and anions(-) Ionic = a bond between 2 atoms of opposite charge (nacl -salt halite)