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Unformatted text preview: r shell with 8e‐. How?
By gaining or losing electrons, or by sharing electrons, atoms can form chemical bonds; bond formation between reactive atoms yields stable molecules . Types: covalent, ionic, & hydrogen bonds •• ••
N 7p7n • • • arrows indicate unpaired outer shell electrons paired electrons • •valence = 3 Covalent Bond Formation
• The octet rule can also be fulfilled when reactive atoms combine to share valence electrons; such interactions lead to the formation of covalent bonds.
– atoms share electrons in joint orbitals • Carbon (4 valence e‐) can form up to four covalent bonds with hydrogen (1 valence e‐), forming methane (CH4):
Different ways to represent the methane molecule: shared orbitals CH4 The “ball & stick” model shows that the covalent bonds are at fixed angles from each other, forming a pyramid‐ like shape (tetrahedron). Characteristics of Covalent Bonds
• Though covalent bonds represent a sharing of valence electrons between atoms, this “sharing” may not be equal. • The difference in electronegativity between two atoms determines the extent of electron sharing.
– Electronegativity: measure of an atoms’ attraction for electron...
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This note was uploaded on 10/16/2010 for the course HE 012928 taught by Professor Storrs,london during the Spring '10 term at École Normale Supérieure.
- Spring '10