BIOL 213 Lecture Notes - Lecture 1: Van Der Waals Force, Covalent Bond, Electron Shell
26 Sep 2016
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Document Summary
Atom: smallest component of element having chemical properties of the element. Atomic mass: mass of 1 protons or 1 neutrons. Element: pure substance made of only 1 kind of atom. Valence electrons: electrons on the outermost energy level of an atom. Isotope: forms of an element with different # of neutrons, and different mass number. Radioisotopes: an isotope that has an unstable nucleus and undergoes radioactive decay. Transforms the atom, sometimes result in a change in the # of protons. Outermost electron shell determines how the atom behaves. If it is full, atom is stable, won"t react with other atoms. Reactive atoms have unpaired electrons in their outermost shell. 2nd shell = 1s 3p (8 e-) Additional shell = 4 orbital (each hold 8 e-) Orbital: region where an electron is found at least 90% of the time. Ionic bonds = bond form as electrical attraction between ions is opposite charges.
