Chapter 8 Chemical Bonding

Formula 2 single bonds between unlike atoms q hf

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: e atoms q HF Figure 7.10 2 Some atoms can form bonds with more than one atom q CCl4 Figure 7.10 2 Multiple Bonds q Can share more than one pair of electrons Can to form double or triple bonds to 2 electron pairs 3 electron pairs electron 2 Comparison of Bonds q Bond Energy (bond strength): single bond < double bond < triple bond q Bond Length (distance between atom centers): single bond > double bond > triple bond q N―N q 1.47 A N=N 1.24 A N≡N 1.10 A 2 Valence Electrons and Number of Bonds q How is the number of bonds formed by a How given atom related to its number of valence electrons? valence q H-C ≡ C-H H-C q H2C= CH2 q H3C−CH3 q CH4 2 Valence Electrons and Number of Bonds q Draw the structure of a molecule that Draw contains 1 C, 1 O and 2 H: CH2O contains 2 8.4 Bond Polarity and Electronegativity q Polar and Nonpolar Covalent Bonds q Polar Bonds – Electrons are not shared Polar not equally equally q Nonpolar Bonds – Electrons are shared Nonpolar equally equally 2 Polarity of Covalent Bonds q Unequal sharing of electrons in a Unequal bond leads to the development of partial charges separated from one another - this phenomenon is called polarity. polarity q The greater the charge separation, The the more polar the bond. Very polar bonds have relative ionic and covalent character of the bond. covalent 3 Bonds: Ionic, Polar Covalent, Non-Polar Covalent q Bonds can be found with a range of Bonds polarities polarities - from completely ionic from - to completely covalent to 3 Electronegativity q Pauling found that HF has a stronger bond Pauling than the average of the H2 and F2 bonds; he than attributed this extra strength to partial ionic character. q From the bond strengths, he assigned values From of electronegativity - the ability of an atom to attract electrons in a bond to itself. attract 3 Electronegativity 3 Trends in Electronegativity q Which Which combinations of elements are more likely to form ionic bonds? ionic q ... covalent bonds? bonds? 3...
View Full Document

Ask a homework question - tutors are online