Chapter 8: Covalent Bonding Because no one wants to be alone.

Slides:



Advertisements
Similar presentations
Chemical Bonding and Interactions
Advertisements

Drawing and Naming Molecules Lewis Dot Structures and Multiple Bonds.
- Lewis structures and bonds - bonding theories
Covalent Bonds! Yeah!  Elements with high electronegativities (non- metals) will not give up electrons. Bonds are not formed by a transfer of electrons,
Chemical Bonding Warm-up What determines the reactivity of a metal? What determines the reactivity of a non-metal?
Covalent Bonding Chapter 8.
Molecular Compounds Section 9.3 and Chapter 8. Nomenclature for Molecular Compounds When two NONMETALS are bonded together: 1.Write the names of the elements.
By Reid Janssen And Ryan Miller. Forces within Bonding Intramolecular and Intermolecular forces Intermolecular forces are attraction between neighboring.
Ch 8 Review.
C HAPTER 8 SEC 8.4 Chemical Bonds C H 8 S EC 8.4 D ETERMINATION OF B OND TYPE ? Bond type: difference in electronegativity? Ionic : 3.3 – 1.7 range of.
Chemical Bonding Chapter 6 Sections 1, 2, and 5. Chemical Bonds A chemical bond is the mutual electrical attraction between the nuclei and valence electrons.
Modern Chemistry Chapter 6 Chemical Bonding
Forces that hold atoms together.  There are several major types of bonds. Ionic, covalent and metallic bonds are the three most common types of bonds.
Zumdahl • Zumdahl • DeCoste
Chapter 6: Bonding… Chemical Bonding  Describe covalent, ionic and metallic bonds  Classify bond type by electronegative difference  Explain why atoms.
Chemical Bonding Bonds form in 2 main ways atoms share electrons electrons are transferred between atoms Type of bond depends on the atom’s electronegativity.
MOLECULAR GEOMETRY AND POLARITY
Chapter 15/16 Bonding.
Chapter 5 Compounds and Their Bonds
Chapter 8 – Covalent Bonding Review of Chapter 7 In Chapter 7, we learned about electrons being transferred (“given up” or “stolen away”) This type of.
Covalent Bonding Molecular Compounds  Describe a covalent bond in terms of the difference in electronegativity of the atoms and the energy changes in.
BONDING AND GEOMETRY Unit 8 Chemistry.
Chemical Bonding Chapter Types of Bonds Ionic and Covalent Bonds Chemical Bonds are the force that holds atoms together in a compound or molecule.
Chapter 8 Covalent Bonding. The Covalent Bond Atoms will share electrons in order to form a stable octet. l Covalent bond : the chemical bond that results.
Quick Review Covalent bond – two atoms held together by sharing electrons -- Usually occurs between nonmetals. Octet Rule – chemical compounds tend to.
Chapter 8 Covalent Compounds. Covalent Bonds Sharing Electrons –Covalent bonds form when atoms share one or more pairs of electrons nucleus of each atom.
Chemical Bonding Chapter 6. Chemical Bond Chemical Bond – an attraction between atoms to hold the atoms together.
A. Ionic Bonding 1. attraction between large numbers of (+) ions and (-) ions 2. results when there is large electronegativity differences 3. generally.
Chemical Bonding Chapter 12.
Covalent Bonding.
Chemical Bonding Bonding within a molecule is called intramolecular attraction –Ionic bonds –Covalent bonds –Polar covalent bonds.
CHEMICAL BONDS Chemical Bond  Mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together.
Chapter 16 Covalent Bonding
Chemical Bonding Chapter 6 General Chemistry Valence Electrons Valence electrons ______________________________ _______________________________________________.
Chapter 6 Chemical Bonding. Sect. 6-1: Introduction to Chemical Bonding Chemical bond – electrical attraction between nuclei and valence electrons of.
Molecular Shape and Polarity The Importance of Geometry in Determining Physical Properties.
Chapter 8 – Covalent Bonding
Covalent Bonding Results from the sharing of electron pairs between two non metal atoms.
Molecular Shape and Polarity The Importance of Geometry in Determining Physical Properties.
Chapter 6 Chemical Bonding.
Covalent Compounds Chapter 8. Section 1, Covalent Bonds –Remember, ionic compounds are formed by gaining and losing electrons –Atoms can also share electrons.
Chapter 6 Covalent Compounds. 6.1 Covalent Bonds  Sharing Electrons  Covalent bonds form when atoms share one or more pairs of electrons  nucleus of.
Covalent Compounds Chapter Covalent Bonds. Covalent Bond The sharing of electrons between atoms Forms a molecule To have stable (filled) orbitals.
Bonding Ionic versus Covalent. Ionic Bonding What is it? Bonding between a metal and a non metal What holds the bonds together? Electrostatic attraction.
Chapter 8.  When two atoms both want to gain electrons they cannot form an ionic bond  They can form a covalent bond  Atoms are held together by sharing.
Chapter 6 Chemical Bonding. Bonding Theory and Electronegativity Atoms want to achieve noble gas configuration- 8 valence e- Some elements have stronger.
Chem I Chapter 6 Chemical Bonding Notes. Chemical Bond – a mutual attraction between the nuclei and valence electrons of different atoms that binds the.
Chemical Bonding Chapter 12. May the force be with you… Chemical Bond: The force that holds 2 or more atoms together and makes them function as a unit.
COVALENT BONDING Chapter 6, Sections 1&2. Electronegativity  A measure of the ability of an atom in a chemical compound to attract electrons from another.
________________: mutual electrical attraction between the nuclei & valence e-’s of different atoms that bond together. The type of bonding is determined.
Chemistry Unit 4 Chapter 8.  Molecule  A neutral group of atoms joined together by covalent bonds  Molecular Compound  Tend to have lower melting.
Chemical Bonding b Chapter 6. Chemical bond b The force (electrical attraction) that binds two atoms together.
Ch. 8 Covalent Bonding Pre AP Chemistry. I. Molecular Compounds  A. Molecules & Molecular Formulas  1. Another way that atoms can combine is by sharing.
COVALENT BONDING.
Unit 11 - Bonding Types of Chemical Bonds Electronegativity Bond Polarity and Dipole Moments Stable Electron Configurations Lewis Structures Lewis Structures.
Chapter 6 Chemical Bonds. Chemical Bonds- the mutual attraction between the nuclei & valence electrons of different atoms that holds atoms together –Bonding.
Chapter 6 Chemical Bonds. Terms: Molecule- a neutral group of atoms held together by covalent bonds Molecular Compound- compound made of molecules Chemical.
Covalent Bond A chemical bond in which electrons are shared. Each atom has access to a full octet (8 electrons). No electrical charges.
Molecules & Covalent Bonding
Bonding.
COVALENT BONDING.
Lewis Dot Structure, polarity, molecule shapes, forces
Chapter 8: Covalent Bonding
Ch. 8 Covalent Bonding.
BONDING Unit 6.
Chemical Bonding Unit 2 Topic 3 Chapter 6.
Drawing Lewis Structures
Ch. 16 Notes---Covalent Bonds
Chapter 8 Covalent Bonding.
Chapter 8 Molecular Compounds.
Presentation transcript:

Chapter 8: Covalent Bonding Because no one wants to be alone.

Objectives 1.Compare and contrast covalent and ionic bonding. 2.Use electronegativity difference to determine the type of a chemical bond that will form between 2 elements. 3.Draw Lewis structures for covalent compounds. 4.Use the VSEPR theory to describe molecule shape, bond polarity, and molecule polarity. 5.Describe the 3 types of intermolecular forces.

Covalent Chemical Bond: a strong attractive force between atoms that form molecules. Molecule – a neutral group of atoms joined together by covalent bonds.

Covalent Bonds Chemical bond between 2 or more atoms sharing electrons 2 atoms = diatomic molecule

Covalent Bonds Nonpolar covalent bonds –Electrons are shared equally –Small difference in electronegativity Polar covalent bonds –Electrons are shared unequally –Large difference in electronegativity

LEARNING CHECK: 1.What are the 2 main differences between ionic and covalent bonds? 2.What are the 2 types of covalent bonds? 3.Which type of bond exhibits higher electronegativity difference?

Ionic Vs. Covalent Bonds

Molecular Compounds and the Octet Rule –Covalent bonds occur by atoms sharing electrons with the goal of getting 8 electrons in their outer energy level. –This forms molecular compounds a.k.a. MOLECULES –Molecular formulas are chemical formulas for covalently-bonded atoms. – END OF PART 1

Lewis Structures & Structural Formulas –The Lewis structure shows both how electrons are shared within the molecule as well as the unshared valence electrons –A structural formula shows us how the atoms are shared in a molecule but does not show the unshared pairs of electrons Example: F–F and H–Cl –Single bonds are one shared pair, a double bond two shared pairs, and a triple bond is three shared pairs of electrons

Drawing Lewis Structures Let’s use the compound C 2 H 2 The NASL Method: 1.Write the electron-dot notation for each type of atom. 2.Chose a central atom. Your choice will be the atom with the greatest number of unpaired electrons. If carbon is present it is in the center. Hydrogen is never in the center.

Drawing Lewis Structures 3. Calculate N (Needed) as the sum of electrons needed for all atoms by the octet rule. Exceptions: H=2, Be=4, B=6. 4.Calculate A (Available) as the sum of all valence electrons. 5.Calculate S (Shared) as the difference between N – A. 6.Divide S by 2 to obtain the number of bonds to be extended from the central atom. 7.Calculate L (Lone-pair electrons or simply “dots”) as the difference between A – S. Place the L dots into the skeleton as to fill the octet of every atom except hydrogen. Remember that hydrogen has only one bond and NO dots. 8.Check that the total number of used electrons is equal to A.

Drawing Lewis Structures Example: H 2 is written as H:H or H–H –Try H 2 O, O 2, and F 2

Resonance Structures Anytime a molecule or ion cannot be correctly represented by a single Lewis structure, it has resonance structures –E–Examples: O 3 SO 4 - NO 3 - –D–Draw a Lewis structure for O 3 –N–Now draw its resonance structure. –G–Got it???

LEARNING CHECK: 1.What is a molecule? 2.How is the octet rule satisfied in molecular compounds (molecules)? END OF PART 2

VSEPR Valence Shell Electron Pair Repulsion –Repulsions between electron pairs makes them orient as far as possible from one another Count the electron pairs on the central atom –If 2 then linearBeCl 2 –If 3 then trigonal planarBF 3 –If 4 then tetrahedralCH 4 –If 5 (rare) then trigonal bipyramidalPCl 5 –If 6 (rare) then octahedralSF 6

LEARNING CHECK: What does the VSEPR theory mean?

VSEPR Unshared electron pairs on the central do play a role in the 3-D geometry of the molecule –W–When we describe the shape of a molecule we refer only to the relative positions of the atoms –E–Examples: NH 3 and H 2 O Trigonal pyramidalBent or Angular

END OF PART 3

Intermolecular Forces Forces of attraction between molecules –Typically much weaker than atomic bonds –Three types: Dipole-Dipole Forces: occur between polar molecules (direction from + to – ) Hydrogen bonds: is like a dipole-dipole, only hydrogen is bonded to a highly electronegative atom (F, O, Cl) London Dispersion Forces: movement of electrons which cause momentary dipole like attractions

Molecular Dipole Moments Dipole moments have positive and negative ends (arrow is negative, tail is positive)Dipole moments have positive and negative ends (arrow is negative, tail is positive) The arrow head is attracted to the tail of another arrowThe arrow head is attracted to the tail of another arrow

Hydrogen Bonding Hydrogen bonds are very similar to dipole-dipole interactions but always involve the positive hydrogen side of a molecule and the negative side of another molecule

LEARNING CHECK 1.How do multiple molecules stay together? 2.Describe how water (H 2 O) molecules stay together.