S-124 What are three different types of chemical bonds?

SPS4 Students will investigate the arrangement of the Periodic Table b.Compare and contrast ionic and covalent bonds in terms of electron movement. SPS2 Students will explore the nature of matter, its classifications, and its system for naming types of matter. b.Predict formulas for stable binary ionic compounds based on balances of charges c.Use IUPAC nomenclature for transition between chemical names and chemical formulas – binary ionic compounds – binary covalent compounds Unit 6 Chemical Bonds

When is an atom unlikely to react? What is one way in which elements can achieve stable electron configurations? How does the structure of an ionic compound affect its properties? 6.1 Ionic Bonding

Stable Electron Configurations –When the highest occupied energy level has 8 electrons, the atom is stable Won’t react Called the octet rule –Electron Dot Diagram A model of an atom showing valence electrons Maximum of eight arranged in pairs of two Electrons will unpair on a side and only pair up if needed 6.1 Ionic Bonding When is an atom unlikely to react?

Ionic Bonds –Atoms transfer electrons to achieve a stable configuration –Metals lose electrons Empty out the valence electron shell They will become positively charged (cation) –Non-metals gain electrons Fill up the valence electron shell They will become negatively charge (anion) 6.1 Ionic Bonding What is one way in which elements can achieve stable electron configurations?

Ionic Bonds –Opposite charges attract each other –Will attract so that the sum of the charges in an ionic compound is zero –For example – a compound made of Aluminum and Fluorine 6.1 Ionic Bonding What is one way in which elements can achieve stable electron configurations? FAlF-F- Al +3 (+3) + (-1) = +2 F-F- (+3) + (-2) = +1 F-F- (+3) + (-3) = 0

Chemical Formula –Notation shows elements and number of elements in a compound –Symbol, subscript for number of each element –Charge is always zero –For ionic compounds, positive is always first 6.1 Ionic Bonding What is one way in which elements can achieve stable electron configurations? F-F- Al +3 F-F- F-F- AlF 3

Practice – Lithium and Oxygen –Charges? –Sum of charges? –What do we add? –Chemical Formula? 6.1 Ionic Bonding What is one way in which elements can achieve stable electron configurations? O -2 Li + Li 2 O (+1) + (-2) = -1 Li + (+2) + (-2) = 0

S-125 Write the correct formula for compounds formed by the combination of A. Cobalt and Oxygen B. Magnesium and Bromine C. Potassium and Nitrogen

S-126 Write the correct formula for compounds formed by the combination of A. Silver and Iodine B. Boron and Phosphorus C. Strontium and Chlorine

How are atoms held together in a covalent bond? What happens when atoms don’t share electrons equally? What factors determine whether a molecule is polar? How do attractions between polar molecules compare to attractions between nonpolar molecules? 6.2 Covalent Bonding

Covalent Bond –Two atoms share a pair of electrons –Each donates one of the two electrons –In an electron dot diagram it is shown by Writing the two elements next to each other Showing the pair between them that is being shared –Can also be shown in a structural model by a line –Covalent bonds form between nonmetals 6.2 Covalent Bonding How are atoms held together in a covalent bond?

Molecule –A neutral group of atoms joined by covalent bonds –Diatomic molecule Elements that in their normal state are bonded to each other Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine, Iodine 6.2 Covalent Bonding How are atoms held together in a covalent bond?

Polar Covalent Bonds –Each different element has a different force of attraction for electrons –Farther right on a period is greater –Higher up a group is greater –This leads to uneven attraction for the electrons in a covalent bond –Any covalent bond between different elements will be polar 6.2 Covalent Bonding What happens when atoms don’t share electrons equally?

Polar and Nonpolar Molecules –Only bonds between the same element are non polar –Molecules are polar depending on their shape Bonds must be polar first Shape must have a way to tell one end from another 6.2 Covalent Bonding What factors determine whether a molecule is polar?

Attraction –Polar molecules are much more strongly attracted to each other than nonpolar molecules Results in higher melting point and a higher boiling point It takes more energy to pull the molecules apart 6.2 Covalent Bonding How do attractons between polar molecules compare to attractions between nonpolar molecules?

What information do the name and formula of an ionic compound provide? What information do the name and formula of a molecular compound provide? 6.3 Naming Compounds and Writing Formulas

Naming Ionic Compounds (Metal and a Nonmetal) –Write the name of the metal –Write the name of the nonmetal, but end the name with –ide –Try MgCl 2 Rb 2 O Ca 3 P Name and Writing What info in name and formula of an ionic compound?

Transition Metals –The name includes the charge –So Fe+3 would be iron (III) –Fe+2 would be iron (II) –The roman numerals are I, II, III, IV, V, VI –Try FeCl 2 Cu 2 O PbO Name and Writing What info in name and formula of an ionic compound?

Transition Metals –Try Titanium (IV) Fluoride Chromium (III) Oxide Lead (II) Nitride 6.3 Name and Writing What info in name and formula of an ionic compound?

S-127 What is the name of A. CuO B. AgCl C. Sr 3 N 2

S-128 What would be the formula for A. Vanadium (IV) Oxide B. Sodium Fluoride C. Tungsten (III) Sulfide

Molecular Compounds –Prefixes are used to tell how many of each element there are –You need to memorize the prefixes. –Try N 2 O 4 CO 2 NI Name and Writing What info in name and formula of an covalent compound? NumberPrefix 1mono (only 2 nd ) 2Di 3Tri 4Tetra 5Penta 6Hexa 7Hepta 8Octa

Molecular Compounds –Try Carbon Monoxide Dihydrogen Monoxide Carbon Tetrachloride 6.3 Name and Writing What info in name and formula of an covalent compound?

S-129 What is the name of A. CBr 4 B. NO C. XeF 6 What is the formula for A. Iron (II) Oxide B. Nitrogen Tribromide C. Iodine

What are the forces that give a metal its structure as a solid? How do metallic bonds produce some of the typical properties of metals? How are the properties of alloys controlled? 6.4 The Structure of Metals

Metallic Bonds –Metal bonding to metal –In metals Valence electrons become a sea of electrons (negative charge) The remaining metal is a cation because it has lost its valence electrons –Form a strong bond between the cations and the sea of valence electrons More valence electrons, stronger bond (see sodium) 6.4 The Structure of Metals What are the forces that give a metal its structure as a solid?

Metallic Bonds –The valence electrons are free to move This allows the electrons to move to conduct electricity –The cations are also free to slide past each other This allows the metals to be malleable 6.4 The Structure of Metals How do metallic bonds produce some of the typical properties of metals?

Alloys –A mixture of two or more elements at least one of which is a metal –Properties are controlled by the elements that are combined –Brass – copper and zinc –Steel – iron, carbon, and other elements 6.4 The Structure of Metals How are the properties of alloys controlled?

S-130 What is the name of A. Ag 3 N B. KrF 8 C. O 2 What is the formula for A. Carbon Monoxide B. Hydrogen C. Copper (I) Sulfide