Chem 121 1st Edition Lecture 11 Outline of Last Lecture I. Formation of IonsII. TrendsIII. Ionic Size and Atomic SizeIV. Electronic AffinityOutline of Current LectureI. Chemical BondingII. Ionic BondingIII. Covalent BondingIV. Chemical FormulasV. Lewis Model/ Lewis Structures- Ionic/ Covalent BondingVI. Naming Simple CompoundsCurrent LectureChemical Bonding- Behaviors of elementso Metals: Lower IE  lose electrons  cationso Nonmetals: Higher IE  gain electrons  anionso Octet Rule: Atoms lose, gain, and share electrons when bonding to attain (become equal to) a noble gas electron configuration- Three Combinations of bonds:o Metal- Metal, Metal- nonmetal, Nonmetal-nonmetalIonic BondingThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Metals and Nonmetals in main groups (VERY IMPORTANT!!!!!)o Metal  lose electrons  cationo Nonmetal  gain electrons  aniono Octet Rule: Atoms lose, gain, or share electrons when bonding to attain (become equal to) a filled outmost (valence) shell of 8 electrons- Group 8A: chemically stable- Metals (s-block): lose valence electrons (by group #)- Nonmetals (p-block): gain electrons- Ionic Bond: The electrostatic attraction between oppositely charged ions- Ions:o Metals cation: metal  loses electronso Nonmetal anion: nonmetal  accepts electronso Electron transfer: metal  nonmetal- Electron Ownership: own by anionso No bond restrictiono Attract as many oppositely charged ions as possible- Ionic lattice: release energy upon formingo Formula Unit: cation-to-anion ratio, no existence of moleculesCovalent Bonding- Covalent Bonding: Bonding in which electrons forming pairs are shared by atoms- Elements: Nonmetal- Nonmetal- Electron Ownership: Between two atomso No covalent bonding beyond bonding atomso Bonding electrons localized within moleculeso Form molecules- Sharing electrons: Nucleus “feels” electron pair all the time (Egg with two yolks)Chemical Formulas- Element symbols and numerical subscripts showing the type and number of each atom present in the smallest unit of the substance- Empirical formulao Relative # of atoms of each element in the compound o Smallest ratio between the bonding elementso Used for all ionic compounds (formula unit)- Molecular formulao Actual # of atoms of each element in a molecule of the compound (Covalent compounds)o Same empirical formula, different molecular formulas- Structural formulao The # of atoms and the bonds between them in a moleculeo Molecular formula showing the bonding between those two elementsLewis Model- Why the difference?- Lewis electron-dot symbols (1916)o Each dot= one valence electron (main group)o One dot on each of the four sides of the element symbol, then pair them until all of the valence electrons are countedo 1A-4A: dots (valence electrons) are unpairedo 5A-8A: dots (valence electrons) start pairingo Same group  same # of valence electrons  same # of dotso Octet: 4 pairs; Duet: 1 pair- Lewis dots and electron configurationo No dot pairing in elements in groups 2A, 3A, and 4ALewis Structures- Ionic Bonding/ Ionic Compounds- Formula of ionic compounds using Lewis symbolso # of electrons lost by metal = # of electrons gained by nonmetal- Cations formed by metals:o Metals losing all the dots ( valence electrons)o No dots around symbolo # of positive charges = # of dots lost- Anions formed by nonmetals:o Nonmetals gaining dots- fill valence shell: only enough to fill the shell (8)o 8 dots around symbol- octet ruleo Core electrons give us Octet Ruleo # of negative charges = # of dots gained- Lewis structures of Ionic Compoundso Two ions together- attraction between ionso Put a charges as a part of the formulaLewis Structures- Covalent Bonding- Covalent bonding (nonmetals)o Goal: to get Octet for each atomo No obvious electron transfero Pair unpaired dots with another atom to attain octet (duet for H)o # of unpaired electrons = # of covalent bondso # of covalent bonds = 8 (2 for H) – group #- Diatomic molecules (containing one covalent bond)o Single bond- one bonding pair of electronso Double bond- two bonding pair of electronso Triple bond- three bonding pair of electronso CO- Carbon monoxideNaming Simple Compounds- General formula: MnXyo M- name of 1st elemento X- name of anion- Anion- single or cluster of nonmetal atoms with negative chargeo Monatomic anion- single nonmetal atom with n- charge Name: Base name (B.N., first syllable of element) + -ide Charge: Group # - 2 (for Hydrogen) or 8( rest of elements) OR look at the location on periodic