Note Taking Guide: Episode 501 Camille Levy Name______________ valence A chemical bond - forms when 2 or more atoms rearrange ____________ electrons stability _____________ to increase ________________. electrons transferred ionic bond - forms when valence _____________ are _____________ from one atom to another loses + cation – atom __________ electrons to become ______ charged gains anion - atom __________ electrons to become ______ charged crystal lattice In ionic compounds the ions are arranged in a ___________ ___________. Strong __________ forces hold the ions together. Properties of ionic compounds: melting boiling high ____________ and ___________ points hard crushed ___________ - not easily ______________ conduct melted _____________ electricity when ___________ or dissolved move ______________ because the ions are free to __________. electrons shared covalent bond - ______________ are _____________, forming molecules _______________. weaker Covalent compounds have ____________ forces holding the molecules _____________ together. Properties of covalent compounds: boiling melting • lower ____________ and ___________ points volatile • Many covalent compounds are _____________ liquids or gases. soft crush • ____________– easier to ___________ conductors • are not ________________ of electricity attraction electronegativity - property that tells how strong an atom’s ____________ electrons is for _____________. higher Since oxygen has a ______________ electronegativity than hydrogen, oxygen tighter partial holds onto shared electrons ____________, giving the oxygen a __________ positive negative charge and the hydrogen a partial _____________ charge. CHEMISTRY: A Study of Matter © 2004, GPB 5.1 polar covalent bonds: unequally • electrons are shared _________________, creating partially charged ends poles or __________. nonpolar covalent bonds: equally • electrons are shared ________________ because atoms have the same electronegativities Electonegativity difference: greater than or equal to 1.7 between 1.7 and 0.3 Type of Bond ionic bond polar covalent less than or equal to 0.3 non polar covalent Examples: Mg and F? Mg is 1.2 and F is 4.0 S and O? S is 2.5 and O is 3.5 3.5 - 2.5 = 1.0 Polar Covalent 4.0-1.2= 2.8 Ionic Bond Program 501, problem set 1: Li and Cl C and O Na and C Cl and Br S and H - ionic bond polar covalent ionic bond non polar covalent polar covalent metallic bond – delocalized electrons are ________________ sea of ___________”) electrons (creates a “____ properties of metals: 1. malleable 2. luster 3. ductile 4. conductors The Chemistry Quiz A. CR1._____ B. CR2._____ A. 3._____ B. 1._____ B. 4._____ CHEMISTRY: A Study of Matter © 2004, GPB 5.2 A. 2._____ D. 5._____