BIOL 1117 Lecture Notes - Lecture 3: Periodic Table, Chemical Bond, Van Der Waals Force
15 Sep 2016
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Document Summary
Elements: simplest form of matter to have unique chemical properties. Atomic number of an element: number of protons in its nucleus: periodic table, 91 elements exist arranged by atomic number, elements represented by one- or two letter symbols, 24 elements have biological role, 6 elements=98. 5% of body mass. Oxygen (o), carbon (c), hydrogen (h), nitrogen (n), calcium (ca), and phosphorus (p: another 6 elements account for just less than 1% of body: Sulfur (s), potassium (k), sodium (na), chlorine (cl), magnesium (mg, and iron (fe: 12 trace elements present in minute amounts. Zinc, copper: other elements such as the heavy metals (e. g. lead), that do not have physiological roles but can disrupt physiological function. Of the 24 biological elements: all are minerals except oxygen, carbon, hydrogen and nitrogen: this is because these can be gaseous so we do not need to eat them. Electrons: in concentric clouds that surround the nucleus.
