1 / 13

Introduction to Bonding and electron dot/ lewis structures

Introduction to Bonding and electron dot/ lewis structures. Chemistry. Why is bonding important??. Without bonding the universe would be a mass of individual atoms. The type of bond defines the properties of a substance. NaCl…shape H 2 O and oil…dissolving. Electronegativity.

nyoko
Download Presentation

Introduction to Bonding and electron dot/ lewis structures

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Introduction to Bonding and electron dot/lewis structures Chemistry

  2. Why is bonding important?? • Without bonding the universe would be a mass of individual atoms. • The type of bond defines the properties of a substance. • NaCl…shape • H2O and oil…dissolving

  3. Electronegativity • Ability of atoms within a molecule to attract electrons

  4. Polar • Describes molecules with an unequal distribution of electrons • (nonpolar = equal)

  5. Covalent • Describes a bond where electrons are shared

  6. Ionic • Describes a bond where electrons are transferred

  7. DETERMINING BOND TYPE • Calculate the difference in electronegativities: > 1.7 = ionic (electrons transfer) 0.3-1.7 = polar covalent (electrons are shared unequally) <0.3 = nonpolar covalent (equal sharing of electrons)

  8. EXAMPLE: 1. H2 a) Calculate the difference in electronegativities: 2.2 – 2.2 = 0  nonpolar covalent (equal sharing) b) Draw the electron dot/Lewis structure: H + H = H H [recall the “duet rule”—H wants 2 e-]

  9. Nonpolar Covalent Bonds • Describes a bond where electrons are shared equally • Less than 0.3 electronegativity difference. • Let’s look at an animation of this with H2: H2 EN=0 (http://www2.gasou.edu/chemdept/general/molecule/polar.htm) (http://web.jjay.cuny.edu/~acarpi/NSC/5-bonds.htm)

  10. EXAMPLE: 2. H2O a) calculate the difference in electronegativities: 3.5 – 2.2 = 1.3  polar covalent (unequal sharing) b) Draw the electron dot/Lewis structure: H + H + O = H O H [recall the “duet rule”—H wants 2 e-]

  11. Polar Covalent Bonds • Describes a bond where electrons are shared unequally • Electronegativity (EN) difference is between 0.3 and 1.7. • Let’s look at an animation of this with H2O and HBr: H2O END=1.4 HBr END=0.7 (http://www2.gasou.edu/chemdept/general/molecule/polar.htm) (http://web.jjay.cuny.edu/~acarpi/NSC/5-bonds.htm)

  12. EXAMPLE: 3. HF a) calculate the difference in electronegativities: 4.0 – 2.2 = 1.8  ionic (electrons are transferred) b) Draw the electron dot/Lewis structure: H + F = H F - +

  13. Ionic Bonds • Describes a bond where electrons are transferred. • Greater than 1.7 electronegativity difference. • Let’s look at an example of this with NaCl: NaCl EN=2.1 (http://www2.gasou.edu/chemdept/general/molecule/polar.htm) (http://web.jjay.cuny.edu/~acarpi/NSC/5-bonds.htm)

More Related