BIOL 243 Lecture Notes - Lecture 2: Unpaired Electron, Ionic Bonding, Chon
28 Aug 2016
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Document Summary
Chem deals w the composition of matter and how it changes. Energy= the capacity to do work: potential= stored or inactive, kinetic= energy of motion, cant be created or destroyed, but can change forms. Matter is anything that has weight and takes up space. Living organisms require about 20 elements: carbon, hydrogen, nitrogen, oxygen, phosphate, and sulfur (chnops) are the most abundant. Attractions between 2 or more atoms are called chemical bonds. Ionic= a bond formed when ions of opposite charges transfer electrons: usually between metal and nonmetal, ex. Covalent= involves a sharing of a pair of electrons (strong: usually between 2 nonmetals (single, double, triple, ex. Co: polar (unequal sharing) or nonpolar (equal) Peptide bonds= the bond between amino acids. Hydrogen bonds=a weak bond between the electropositive h of one molecule and the electronegative o or n of another: ex. Properties of water: adhesion, cohesion, surface tension, high heat capacity; high heat of vaporization, universal solvent (polarity)
