Post on 24-Dec-2015
Welcome to Chemistry Welcome to Chemistry Turn in electron configurationTurn in electron configuration Notes on BondingNotes on Bonding PracticePractice
Warm upWarm up
Write noble gas configuration for Write noble gas configuration for Cu and AgCu and Ag
Introduction to Introduction to Chemical BondingChemical Bonding
Chapter 6, Section Chapter 6, Section 11Get ready to take
notes
What is a bond?What is a bond?
A bond is an electrical attraction A bond is an electrical attraction between valence electrons and between valence electrons and protons of different atomsprotons of different atoms
Why bond?Why bond?
Nature likes things easy (ie. low Nature likes things easy (ie. low energy) and bonding causes energy) and bonding causes atoms to be more stable.atoms to be more stable.
2 Main types of bonds2 Main types of bonds
Covalent – electrons are shared Covalent – electrons are shared between nonmetalsbetween nonmetals
Ionic – electrons are transferred Ionic – electrons are transferred from cation to anionfrom cation to anion– Might want to refresh your memory Might want to refresh your memory
on electronegativity (p. 151)on electronegativity (p. 151)
What determines type What determines type of bond???of bond???
Electronegativity!Electronegativity!– Subtract the EN of Subtract the EN of
the 2 atoms, then . . .the 2 atoms, then . . . If difference is equal If difference is equal
to or more than 1.7 to or more than 1.7 = ionic= ionic
If difference is btwn If difference is btwn 0.3 & 1.7 = polar 0.3 & 1.7 = polar covalentcovalent
If difference is less If difference is less than 0.3 = non-polar than 0.3 = non-polar covalentcovalent
What were those What were those bonds again?bonds again? Ionic = electrons are transferredIonic = electrons are transferred Polar Covalent = electrons are shared, but Polar Covalent = electrons are shared, but
not equallynot equally Non-polar covalent = electrons are shared Non-polar covalent = electrons are shared
equallyequally
How ‘bout some How ‘bout some examples?examples? What type of bond would form What type of bond would form
between the following elements?between the following elements?– Hydrogen & SulfurHydrogen & Sulfur– Cesium & FluorineCesium & Fluorine– Carbon & chlorineCarbon & chlorine– 2 Oxygen atoms2 Oxygen atoms
PracticePractice S and HS and H
– 2.5-2.1=0.42.5-2.1=0.4– polar covalent (b)polar covalent (b)
Cs and FCs and F– 4.0-0.7=3.34.0-0.7=3.3– Ionic (c)Ionic (c)
C and ClC and Cl– 3.0-2.5=0.53.0-2.5=0.5– polar covalent (b)polar covalent (b)