Chapter 7-8. Periodic Chart is organized relative to periodic properties (by families) Chemical...
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Transcript of Chapter 7-8. Periodic Chart is organized relative to periodic properties (by families) Chemical...
Chapter 7-8
Periodic Chart is organized relative to periodic properties (by families)
Chemical Bonding occurs in order to follow the Octet Rule Octet Rule states that a point of stability
within chemicals occurs with a s2p6 configuration
Distance between nucleus and outmost electron in a bonded atom
Energy needed to remove the most loosely held electron from the atom
Other points of stability occur within chemistry Full subshells (s2 p6 d10 f14) ½ full subshells (s1 p3 d5 f7)
Distance from the nucleus to the outermost electron in an atom
Cations – smaller than the original atom
Anions – larger than the original atom
Energy released when an additional electron is acquired by the atom(Desire for additional electron)
Metal Properties
Nonmetal Properties
Metalloids
Also follows periodic properties because electrons in the outer energy level are the makers of properties
Ability of an atom to attract electrons to itself, when involved in bonding
Differences in electronegativity (END) determines bond character Large difference (END > 1.67) is strongly
IONIC Small difference(END<1.67) is strongly
COVALENT
Chapter 7 #16,18,19,24,32
Chapter 8#1,2,4,8,10,23,24,38
Complete transfer of electrons due to large differences in electronegativity (END>1.67)
Metal + Nonmetal Charged particles held together by
electrostatic force of attraction called Lattice Energy
ionic bonding example
Bond Character (mostly due to charged ions) Intraparticle (within)
Strong bond High solubility (strong electrolyte) High conductivity in aqueous solution
Interparticle (between) Usually solids High melting point Crystalline (ionic compound) Hard
Sharing of electrons due to small differences in electronegativity (END < 1.67)
Nonmetal + Nonmetal Held together by sharing of electron to
satisfy octet rulecovalent bonding example
Pure Covalent Bond (equal sharing of e-) Polar Covalent Bond (unequal sharing or e-)polar molecule
Polarity of a covalently bonded particle effects a variety of properties and is an important concept in chemistry
Polarity occurs when there is an ASYMETRICAL CHARGE DISTRIBUTION and a
dipole or polar molecule is created
Bond Character mostly due to sharing of electrons Intramolecular (within)
Weak bond Low solubility (remains intact as molecule) Low conductivity in aqueous solution
Intramolecular (between) Usually gas, liquid or low melting point solid Low boiling point Amorphous (noncrystalline)
Ex: NH3 , CH4 , O2
Delocalized electrons travel among the nuclei “SEA OF ELECTRONS”
Properties Very strong bonds Highly conductive in solid form High melting point