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Unformatted text preview: • Bond is union b/w electrons in outer shell of atoms • Atoms bond to form molecules • Molecules may contain atoms of only one element O2 • Molecules of compounds contain more thatn one element H2O Important Bonds in Biological Molecules • Ionic Bonds o Attraction between Ions Sodium has 1 electron in outer shell: chlorine has 7 Sodium can lose 1 and chlorine can gain it Sodium becomes a + ion Chlorine becomes a - ion • Covalent Bonds o Atoms share a pair or pairs of electrons to fill outermost shell Single covalent bond • Plus 1 pair electrons Double covalent bond • Plus 2 pairs Triple • plus 3 o Nonpolar if atoms share electrons equally Hydrogen gas (H-H) o Polar if electrons spend more time orbiting one atom and less around another Fig. 2-4 • Hydrogen Bonds...
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- Spring '08
- Atom, Electrons, Electrons- negative charge, outer shell Atoms, charge Fewer electrons, atoms Atoms bond