BIOL 1117 Lecture Notes - Lecture 7: Chemical Element, Hydrogen Bond, Atomic Number
3 Oct 2018
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Document Summary
A chemical element is the simplest form of matter to have unique chemical properties. Each element is identified by an atomic number which is number of protons in element. The elements are represented by one- or two-letter symbols. Twenty-four elements have biological roles with normal physiological roles in the human body. Six of 24 elements account for 98. 5% of the body"s mass: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Another 6 elements account for 0. 8% of body mass: sulfur (s), potassium (k), sodium (na), chlorine (cl), magnesium (mg), and iron (fe) (need to know 12 names and symbols). The remaining 12 elements are known as trace elements because each found in minute amounts (e. g. , zn and cu) and make up. 0. 7% of the body"s weight ( do not need to know names of trace elements ). Other elements, such as the heavy metals (e. g. , lead), that do not have physiological roles can disrupt physiological function.
