Post on 27-Jun-2020
CHEMICAL BONDING
Atoms & Ions
An Ion vs an Atom?● A stable atom has equal # of p+& e-.● Losing an e- makes atom POSITIVE.● Gaining an e- makes atom NEGATIVE.
Ex: Na Atom vs Na Ion (cation)
Ex: Cl Atom vs Cl Ion (anion)
What did you notice about the ions?
Losing an e- decreases the size of the atom and gaining e- increases the size of an atom.
Chemical Bonding
● Valence electrons are the electrons involved in bond formation. Consider:
● Ions● Lewis Dot Structure(use valence e-)● Stable Octet (or Duet)
Octet Rule vs Duet Rule
Atoms reacts with other atoms to have stable octet.When atoms react bonds are formed.Octet Rule: Atoms want 8 e- in their valence shell. Duet Rule: Only applies to Hydrogen. Needs two valence e-
Ex: Lewis Dot Structure & Bonds
Ex: Duet Rule
Types of Bonding
Ionic Bonds: Transfer of e-
Between Metal (Cation) & nonmetal(anion)Covalent (Molecular) Bonds:
Share e- Between a nonmetal & a nonmetal(anions)Metallic Bonding:
Between metals
Types of Bonding
Ionic Bonds: NaCl
Which ball is the Na and how did you figure it out?
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Types of Bonding
Covalent Bonding
Metalic Bonding
F−
Review:Viedo
N3− O2− F−
Ionic & Covalent Bond Review
Metallic BondingNa1+ B3+ Mg2+
B3+
How did we get here?
● Count the valence e- for each atom.
● Find the total # of e-● Choose the central atom. ● Carbon always is the
central atom in a structure● Connect other atoms to the
central atom.
Methane: CH4
STOP HERE!!!
Covalent Bonding
● Covalent bonds occurs
between nonmetals
● They share e-
1. Polar Covalent:
Uneven distribution
(share) of e-
2. Non-polar covalent:
even
distribution(share) of
e-
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Ex: Covalent Bonding
● Polar Covalent
● Non-polar
covalent
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Naming Common Ions
Metals(cation): Name stays the same.Ex: Li (Lithium atom) Li+ ( Lithium Ion): Lithium
Nonmetal(anion): Name takes -ide at the end.Ex: Cl (Chlorine atom) Cl- (Chlorine Ion): Chloride ALWAYS WRITE: CATION (METAL) FIRST AND ANION (NONMETAL) SECOND
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Complete the names of the following ions. Ba2+ Al3+ K+
_________ __________ _________
N3− O2− F−
_________ __________ _________
P3− S2− Cl− _________ __________ _________
Learning Check
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Ba2+ Al3+ K+
Barium Aluminum Potassium
N3− O2− F−
Nitride Oxide Fluoride
P3− S2− Cl−
Phosphide Sulfide Chloride
Solution
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Is it Ionic or Covalent? Write the names of the
following compounds. 1) CaO ___________
2) KBr ___________
3) Al2O3 ___________
4) MgCl2___________
Learning Check
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Write the names of the following compounds: All are Ionic
1)CaO calcium oxide2)KBr potassium bromide3)Al2O3 aluminum oxide4)MgCl2 magnesium chloride
Solution
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Learning Check
Write the formulas and names for compounds of the following ions:
Br− S2− N3−
Na+
Al3+
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Solution
Br− S2− N3−
Na+
Al3+
AlNaluminum nitride
Al2S3aluminum sulfide
AlBr3aluminum bromide
Na3Nsodium nitride
Na2Ssodium sulfide
NaBrsodium bromide
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Transition Metals and Ionic Bonds Roman numeral USED FOR TRANSITION
METAL CHARGE. Transition metal CHARGE Will be given.
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Example:
Chromium: Cr3+ Oxygen: O2-
Criss cross charges to write formulaRemember Cr is a transition metal.Cr3+ O2- Cr2O3
Name the compound: Cr2O3: Chromium(III) oxide
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Naming FeCl2To name FeCl21. Determine the charge of the cation from the formula
Fe2+ Cl- Fe ion = 2+2. Cation name stays the same and add Roman numeral in
parentheses to show the cation charge.Fe2+ = iron(II)
3. Write the anion with ide ending. Cl- Chloride 4. Criss cross the charges. Fe2+ Cl1- FeCl2 = iron(II) chloride
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Learning Check
Select the correct name for each.A. Fe2S3
1) iron sulfide 2) iron(II) sulfide 3) iron(III) sulfide
B. Cu2O 1) copper oxide 2) copper(I) oxide 3) copper(II) oxide
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Writing Formulas
Write a formula for potassium sulfide.1. Identify the cation and anion. potassium = K+ sulfide = S2−
2. Balance the charges. K+ S2−
K+
2(1+) + 1(2-) = 0(neutral)
3. 2 K+ and 1 S2− = K2S
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Solution
The correct formula isA. Copper (I) nitride
Cu3N Need 3Cu+ and 1N3-
B. Lead (IV) oxide Pb2O4 = PbO2 Need 1Pb4+ and 2O2-
(It is simplified)
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Learning Check
What is the correct formula for each of the following?
A. Copper(I) nitride 1) CuN 2) CuN3 3) Cu3N
B. Lead(IV) oxide 1) PbO2 2) PbO 3) Pb2O4
Example
CO:
N2Cl4:
Carbonmonoxide
diNitrogentetrachloride
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Guide to Writing Formulas from the Name
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Naming Ionic Compounds with Variable Charge Metals