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Why does bonding occur?
•Bonding occurs to maximize stability of the atoms involved.
•More stable = LOWER potential energy
Bond types• Dependent on the difference between the __________________ of the elements involved in bond▫Electronegativity
Ability of an atom to ________________ Highest found in _______________ _________ are not ranked
Bond Types (cont)
•To Determine Type▫Subtract the electronegativities▫If difference is
______ – bond is non-polar covalent ______- bond is polar covalent Greater than 1.67- ______
Bonding is all about the electrons!• Bond type tells us what will happen to the electron(s)
• Octet rule will give us an idea of how many electrons will be involved▫Have to look at __________________▫Remember most atoms are stable with
___▫Common exceptions
H, He, Li, and Be can be stable with 2 B is stable with 6 Elements with d orbitals (can have
more than 8)
Ionic bonding• Ionic bonding involves the ______ of valence electrons.
• Creates _____▫Cation- + ion (___ electrons)▫Anion- - ion (____ electrons)
•Ions of opposite charges are attracted to each other (the attraction is the bond)
Ionic Compounds
•Will often form a _____ structure
•Formulas give the ___________ number ratio between the ions
Formulas
•Elements in the compound are listed with the number of atoms of each type listed as ___________▫For example, NaCl
Has a ___ ratio of Na+ ions and Cl- ions▫CaI2
Has a ___ ratio of Ca+2 ions to I- ions
Formulas (cont.)
•More complex formulas can have parenthesis with a subscript on the outside
•The subscript on the outside applies to all elements ___ the parenthesis ▫For example, Al(NO3)3
Has __ Al atom ___ N Atoms And ___ O atoms
Binary Compounds
•Compounds only containing ___________ of elements▫For example
H20 FeI3
NaCl Ag2S CaBr2
Ionic Compounds: Binary
•Binary: Metal bonded with Nonmetal ▫Type 1- Metal comes from Group
___________
▫Type 2- Metal comes from Group _________ Transition metals are multivalent (can take
multiple charges) Except Ag (___), Cd (___), and Zn (___)- treat
these like type 1
Binary Compounds: Type 1 • Compound made from a metal from group 1, 2, Al, Ag, Cd,
or Zn with a nonmetal (ionic bond)▫ For example: NaCl, BeF2, Al2O3, K2S
• Metal forms a cation▫ Group 1- ___▫ Group 2- ___▫ Al- ___▫ Ag- ___▫ Cd- ___▫ Zn- ___
• Nonmetal forms an anion▫ Sometimes Group 14- ____▫ Group 15- ____▫ Group 16-____▫ Group 17- ____
Creating Type 1 Formulas
•Steps1. Determine the charge of the ion that each
element will form2. Determine how many ions of each type
will be needed to make the overall charge of the compound zero (neutral)…put each number as subscripts after that element’s symbol
3. Make sure the formula is reduced to its simplest form
Creating Type 1 Formulas (cont)•For example,
▫What is the formula for a compound made of calcium and bromine?
Ca2+
Br-
Br-
Naming Type 1 Compounds
•Base Name ________▫Metal is named first▫Make sure to change the ending of the
anion to -ide
▫For example: NaCl is ___________ CaBr2 is ____________ Li2O is _____________
Binary Compounds: Type 2 • Compound made from a metal from group 3-12
(transition metals or multivalent metals) with a nonmetal (ionic bond)▫ For example: FeCl2, FeCl3, Cu2S3
• Metal forms a cation▫ Charges vary from element to element▫ Most of the transition elements can have several
different charges• Nonmetal forms an anion
▫ Sometimes Group 14- -4▫ Group 15- -3▫ Group 16- -2▫ Group 17- -1
Creating Type 2 Formulas
1. Determine the charge of the anion (the charge of metal will be given to you)
2. Determine how many ions of each type will be needed to make the overall charge of the compound zero (neutral)…put each number as subscripts after that element’s symbol
3. Make sure the formula is reduced to its simplest form
Creating Type 2 Formulas (cont)•For example,
▫What is the formula for a compound made of iron (+2) and chlorine?
Fe2+
Cl-
Cl-
Naming Type 2 Compounds• Base Name + Roman numeral for charge of
metal▫Metal is named first▫Make sure to change the ending of the anion to -ide▫After the name of the metal, the charge of the
metal needs to be put in Roman numerals in parenthesis (because we can’t just look up the charge on the periodic table)
▫For example FeCl2 is ______________ Fe2O3 is _____________ CrS is _______________
Other Ionic Compounds: Polyatomic Ions• Polyatomic ions- two or more atoms combined
that have an overall charge (form an ion)
2-
CO32-
+
NH4+
Polyatomic Names• 10 Polyatomic Names to memorize• Others can be built off of those names
▫Base is __________▫One less oxygen is ___________
• For example:▫NO3
- is ______________
▫NO2- is _____________
Compounds with Polyatomic Ions•Can be
▫Type 1 metal (groups 1, 2, Al, Ag, Cd, or Zn) cation bonded with a polyatomic anion For example: Mg(NO3)2, Cs2SO4, Ca(IO3)2
▫Type 2 metal (transition metal) cation bonded with a polyatomic anion For example: NiSO3, Fe2(CO3)3
▫Or, a polyatomic cation bonded with a nonmetal (treat like a type 1) NH4Cl, (NH4)2O
▫All of these are ionic bonds
Creating Formulas for Compounds with Polyatomic Ions1. Determine the charge of the cation and aniono Polyatomic ion- charto Type 1 metal and nonmetals- determine charge from
group # on periodic tableo Type 2 metals- charge will be given to you
2. Determine how many ions of each type will be needed to make the overall charge of the compound zero (neutral)…put each number as subscripts after that element’s or polyatomic ion’s symbol
o If a subscript is placed after a polyatomic ion, the ion should be put in parenthesis with the subscript after it.
3. Make sure the formula is reduced to its simplest form
Creating Formulas for Compounds with Polyatomic Ions (cont)•For example,
▫What is the formula for a compound made of potassium and the polyatomic ion hydroxide?
Creating Formulas for Compounds with Polyatomic Ions (cont)•For example,
▫What is the formula for a compound made of gold (+2) and the polyatomic ion phosphate?
Creating Formulas for Compounds with Polyatomic Ions (cont)•For example,
▫What is the formula for a compound made of the polyatomic ion ammonium and bromide?
Naming Compounds with Polyatomic Ions• Compounds with
▫ Type I metals and a polyatomic anion (base name without –ide) Same as before except polyatomic ion name is the
second name (do not change the ending to –ide) For example: LiC2H3O2 is lithium acetate
▫ Type II metals and a polyatomic anion (base name without –ide but with Roman numeral) Same as before except polyatomic ion name is the
second name (do not change the ending to –ide) For example: Sn(ClO3)2 is tin (II) chlorate
▫ A polyatomic cation and a nonmetal (base name) Polyatomic ion name comes first, the second name is
the name of the nonmetal with the ending changed to –ide For example: NH4F is ammonium fluoride