BIO-0013 Lecture Notes - Sodium Hydroxide, Lone Pair, Atomic Number
28 Jan 2014
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Document Summary
Overview of today"s topics: (chapter 2: sections 2. 2, 2. 3, 2. 5) Bioskills 6&8 in appendix: atomic structure: atomic number, electron orbitals, chemical reactivity, and. Bond angles: covalent and ionic bonds, polarity of water, acids and bases. Electrons occupy orbitals (2 e- in every orbital), and orbitals are grouped into electron shells: Shell 1: 1 s orbital (2 e- total) Shell 2: 1 s orbital and 3 p orbitals (8 e- total) Shell 3: 1 s orbital, 3 p orbitals and 5 d orbitals (18 e-) total. The lower the shell number, the closer to the nucleus and the lower the energy. Chemical reactivity is largely driven by the fact that atoms are most stable when they have a filled outer shell of electrons (the noble gas configuration). The number of unpaired electrons in the outer shell is the valence: chemical bonding can stabilize valence shells through electron sharing, covalent bonds represent electron sharing:
