Types of Bonds Topic 3 lesson 4

Essential Questions 1. How are electrons involved in bond formations? 2. What types of bonds form between atoms? 3. How do bonds determine certain properties of compounds?

Lewis Dot structure Review A.  X would be the electron dot formula for 1) Na 2) K 3) Al   B.  X  would be the electron dot formula  1) B 2) N 3) P

Valence electrons are involved in bonding. Why do Atoms Bond? To become stable. V = ____ Valence electrons are involved in bonding.

The combining of atoms to form molecules or compounds. What is a Chemical Bond? The combining of atoms to form molecules or compounds. Poisonous gas Soft, metal + =

Ionic Bonding Covalent Bonding forms ionic compounds transfer of e- forms molecules sharing e-

Types of Chemical Bonds 1. Ionic Bonds: formed when atoms lose or gain e- Atoms start off neutral. When they lose or gain e-, they become ions. Charges must be equal IONS are charged atoms Occurs between a METAL and a NONMETAL

Ionic Bonds Metal to Nonmetal 19 Ionic Bonds Metal to Nonmetal Electrons either taken or given away Sodium Chlorine + Opposites attract

Losing & Gaining Electrons Nonmetals form ANIONS (-) Metals form CATIONS (+) Na Give Away Nonmetals form ANIONS (-) Cl Take in

The (-) ion and (+) ion attract. Opposites Attract The (-) ion and (+) ion attract. Na Cl (1+) (1-) Na Cl A neutral COMPOUND

Polyatomic Ions are ions that are made of more than one ion. Poly meaning “many” Metal & Nonmetal Positive & Negative charge End in ide, ate or ite Names of Ionic Compounds First, take the name of the positive metal element Second, take the name of the negative, nonmetal element and give it an –ide ending Third, combine the two names. Example: BaI2 1: barium 2: Iodine…add ide…Iodide 3: barium iodide If the negative ion is a single element End of it’s name changes to –ide NaCl Sodium Chloride MgO Magnesium Oxide If the negative ion is polyatomic Ends with ate or ite NH4NO3 ammonium nitrate (fertilizer)

The Strongest wins the battle and loses the bone (electron) Ionic Bonds The Strongest wins the battle and loses the bone (electron)

Ionic Bonds An ionic bond is the resulting attraction for an anion and a cation after an electron is transferred from the metal to the non-metal

Properties of Ionic Compounds Have properties that are different from their original elements. Hard brittle solids (Crystal) high melting points When melted or dissolved in water, they conduct electric current.

Practice Ionic Bonds On your white board, with blue and red chips, illustrate the following Ionic bonds Written on the board Blue =Metals Red= Non-metal

Diatomic Molecules -atoms of the same element share e- Types of Chemical Bonds Covalent Bonds: formed when atoms share e-; occurs b/t two nonmetals Diatomic Molecules -atoms of the same element share e- Cl Cl BrINClHOF

Covalent Bonding Dogs of equal strength

Covalent Bonds A covalent bond exists when two electrons are shared by two non-metallic atoms

Covalent Bond: formed between two non-metals. Ionic or Covalent? Ionic Bonds: formed between a metal & non-metal. Covalent Bond: formed between two non-metals. molecules

Complete Covalent Map

Electron Sharing and Number of Bonds The force that holds atoms together in a covalent bond is the attraction of each atom’s nucleus for the shared pair of electrons. Single Bond (All atoms are stable- one bond) Hydrogen needs two to be stable and Carbon needs 4 to be stable. Both win.

Molecular vs. Ionic Molecular (Covalent) Ionic Lower melting point Lower boiling point Does not conduct electric current when dissolved or melted High melting point High boiling point Conduct electric current when dissolved or melted

https://www.brainpop.com/science/matterandchemistry/chemicalbonds/ Intro to Ionic and Covalent Compouds Coloring WS

Types of Chemical Bonds *Accounts for many physical characteristics of metals, such as strength, malleability, conduction of heat and electricity, etc. 3. Metallic Bonds: formed when metals bond with other metals. (sea of electrons) Types of Chemical Bonds

Mellow dogs with plenty of bones to go around ! Metallic Bonds Mellow dogs with plenty of bones to go around !

Metallic Bonding Metallic bonds are best characterized by the phrase "a sea of electrons”

Metals Form Alloys Metals do not combine with metals. They form Alloys which is a solution of a metal in a metal. Examples are steel, brass, bronze and pewter.

A quick Review of Bonds: Ionic Metal (+) Nonmetal (-) Transfer of electrons creates ions that attract. Nonmetal Nonmetal Covalent The sharing of electrons creates molecules . (BrINClHOF) Metal Metal Metallic Metal electrons Metal Metal All electrons are shared in a “sea of electrons.”

Practice Compete the worksheet “ “

when electrons are shared equally NONPOLAR COVALENT BONDS when electrons are shared equally H2 or Cl2

2. Non-polar Covalent bonds- Two atoms share one or more pairs of outer-shell electrons. Neither atom becomes charged because they are pulled equally. Fluorine Atom Fluorine Atom Oxygen Molecule (O2)

when electrons are shared but shared unequally POLAR COVALENT BONDS when electrons are shared but shared unequally H2O

Polar Covalent Bonds: Unevenly matched, but willing to share.

- Water is a polar molecule because oxygen is more electronegative than hydrogen, and therefore electrons are pulled closer to oxygen. The atom with the stronger pull gains a slightly negative charge, and the atom with a weaker pull gains a slightly positive charge