1. CHAPTER 7 CHEMICAL FORMULAS AND BONDING Date _____________
COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Ionic compounds
(Elemental) Composition _____________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
metal + nonmetal (EN relatively large)
sodium chloride
NaCl
copper sulfate
Cu(SO4)
chalcocite
CuS
calcium oxide
CaO
potassium nitrate
K(NO3)

2. electrons are transferred
Ionic compounds – Sodium Chloride as an example
11Na ____________________ 17Cl ________________________
Na Cl
EN(Na) = _____ EN(Cl) = _____
11Na+ ____________________ 17Cl- ________________________
electron
configuration
1s22s22p63s1
1s22s22p63s23p5
electron dot
diagram
1.0
3.0
enough atoms transfer enough
electrons so that each resulting ion
ends up with a full outer shell (FOS)
(or full / ½-full sublevels or close…)
electrons are transferred
(from the metal atom
to the nonmetal atom)
electron
configuration
1s22s22p6
1s22s22p63s23p6 - +
electron dot
(aka Lewis dot
diagram
structure)

3. +1 -1 1s22s22p6 1s22s22p63s23p6 - attract ionic bond
11Na+ ____________________ 17Cl- ________________________
Na Cl
1s22s22p6
1s22s22p63s23p6 + - e- e- e- e-
inner shell (core)
electrons e- e- e-
10e-
2e- e-
+17
+11 e-
outer shell
electrons e- e- e- e- e- e- e-
represents ____________
____________
a sphere of
+1 charge +1
represents ____________
____________
a sphere of
-1 charge -1 e-
+17 e-
+11
attract
ionic bond

4. Cl- Cl- Na+ Na+ Na Cl Na Cl
In a typical chunk (crystal) of sodium chloride, (say the size that comes out
of your salt shaker - 1mm3), there would be ~21019 ions of sodium and of chlorine
(20,000,000,000,000,000,000 or 20 billion billion)
Okay, well…. What if there were 2 atoms each of sodium and chlorine ?
Na Cl Na Cl
Cl-
Cl-
Na+
Na+
bond
bond
too!
bond
remember, ions are spheres of charge…
there’s no side of the ion that is more positive or negative than the other side….
(and the charges do not go away when the ions bond)
so, one side of each ion is just as “sticky” as the other…
so…

5. Cl- Cl- Cl- Cl- Cl- Na+ Na+ Na+ Na+ Na+ Na Cl Na Cl Na Cl Na Cl Na Cl
What if there were 5 atoms each of sodium and chlorine ? Na Cl Na Cl Na Cl Na Cl Na Cl
Cl-
Cl-
Na+
Na+
bond
bond
bond
bond
bond
bond
bond
Cl-
Cl-
Na+
Na+
bond
bond
bond
bond
bond
Cl-
Na+
bond

6. Cl- Cl- Na+ Na+ Na Cl but… to give no one… it to hey I’ve got an
electron to give….
but…
me too…
no one…
me too…
to give
it to
What if there were 5 atoms of sodium and 2 atoms of chlorine Na Cl
Cl-
Cl-
Na+
Na+
bond
bond
bond

7. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Ionic compounds
(Elemental) Composition _____________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
metal + nonmetal (EN relatively large)
electrons transferred from metal atom to nonmetal atom,
until one of them (metal or nonmetal or both) runs out
forms cations (+) and anions (-) attract (bond)
sodium chloride
NaCl
copper sulfate
Cu(SO4)
chalcocite
CuS
calcium oxide
CaO
potassium nitrate
K(NO3)

8. Cl- Cl- Na+ Na+ Na Cl Na Cl
In a typical chunk (crystal) of sodium chloride, (say the size that comes out
of your salt shaker - 1mm3), there would be ~21019 ions of sodium and of chlorine
(20,000,000,000,000,000,000 or 20 billion billion)
Okay, well…. What if there were 2 atoms each of sodium and chlorine ?
Na Cl Na Cl
Cl-
Cl-
Na+
Na+
bond
bond
too!
bond
remember, ions are spheres of charge…
there’s no side of the ion that is more positive or negative than the other side….
(and the charges do not go away when the ions bond)
so, one side of each ion is just as “sticky” as the other…
so…

9. Cl- Cl- Cl- Cl- Cl- Na+ Na+ Na+ Na+ Na+ Na Cl Na Cl Na Cl Na Cl Na Cl
What if there were 5 atoms each of sodium and chlorine ? Na Cl Na Cl Na Cl Na Cl Na Cl
Cl-
Cl-
Na+
Na+
cations bond to anions
bond to cations
bond to anions
bond to anions….
until the ions run out
bond
bond
bond
bond
bond
bond
bond
Cl-
Cl-
Na+
Na+
bond
bond
bond
bond
bond
how many atoms of each element there are to start with
determines how many ions are bonded together in the “chunk”
Cl-
Na+
bond

10. cations bond to anions
bond to cations
bond to anions
bond to anions….
until there are no more ions
how many atoms of each element there are to start with
determines how many ions are bonded together in the “chunk”
so,…..
no two “chunks” of sodium chloride will necessarily have the same number
of ions of each element ________________________________
what is the same between each stable chunk ?
***KEY*** the total charge from all the cations must
_______________________________________________________________
in a stable “chunk”
equal the total charge from all the anions to be neutral / stable

11. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Ionic compounds
(Elemental) Composition _____________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
metal + nonmetal (EN relatively large)
electrons transferred from metal atom to nonmetal atom,
until one of them (metal or nonmetal or both) runs out
forms cations (+) and anions (-) attract (bond)
cations bond to anions bond to cations bond to anions
sodium chloride
NaCl
copper sulfate
Cu(SO4)
bond to cations bond to …. until they run out
AND the structure is neutral
chalcocite
CuS
calcium oxide
CaO
potassium nitrate
K(NO3)

12. general
definition
Chemical Formula of a substance (any substance) represents :
_____________________________________________
chemical formula for sodium chloride (ionic compound)
for 1 atom each of sodium and chlorine _________________
for 2 atoms each of sodium and chlorine _________________
for 5 atoms each of sodium and chlorine _________________
for 6,667,000 atoms of each… __________________________
which is correct ? __________________
what is constant (the same) between them ? ______________
which is used ? ___________________
why ? ________________________
so, the chemical formula for ionic compounds is written as :
_________________________________________________
called : ________________________________
the types of elements in the substance
AND the number of atoms/ions of each
in a piece of the substance
Na+1Cl-1
Na+2Cl-2
Na+5Cl-5
Na+6,667,000Cl-6,667,000
they all are
the ratio of Na+ to Cl-
Na+1Cl-1
the simplest (the smallest whole number ratio)
the smallest whole number ratio of ions of the elements
in a stable (neutral) unit of the substance
a formula unit

13. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Ionic compounds
(Elemental) Composition _____________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
metal + nonmetal (EN relatively large)
copper sulfate
Cu(SO4)
electrons transferred from metal atom to nonmetal atom,
until one of them (metal or nonmetal or both) runs out
sodium chloride
NaCl
forms cations (+) and anions (-) attract (bond)
cations bond to anions bond to cations bond to anions
bond to cations bond to …. until one runs out
AND the structure is neutral
the smallest whole number ratio of ions
of the elements in a stable (neutral) unit of the substance
(the stable unit is called a formula unit)
chalcocite
CuS
calcium oxide
CaO
potassium nitrate
K(NO3)

14. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Covalent compounds
fluorine F2
water H2O
carbon dioxide CO2
nitrogen N2
oxygen O2
DNA
C1000’sH1000’sN1000’sO1000’sP1000’s
isopropanol
C3H8O
polyacrylic acid
(C3H4O2)n
crude oil CxHy
proteins – ex: collagen
C5978H9285N1835O1941S31
vitamin C
C6H8O6
fats C~40H~100O3

15. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Covalent compounds
(Elemental) Composition ______________________________________
___________________________________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
(EN relatively small) nonmetal + nonmetal
OR metal + metal OR metalloid + any

16. - + H O H EN not equal H O H so, 1s22s22p4 1s1 1s1
Covalent compounds – Water as an example
8O ____________________ 1H ___________
“wants” ________ has ______
so, need __________
H O H
EN(O) = _____ EN(H) = _____
H O H EN not equal H O H
so,
electrons shared ______________
_______ has _________________
covalent bonding : _________________________________________________
_________________________________________________
1s22s22p4
1s1
1H ___________
1s1
2e-
1e-
another H atom
electrons are shared in pairs
1 shared pair = 1 covalent bond
3.5
2.1
electrons shared
(higher probability of the shared electrons
being on/at the oxygen atom) - +
a bigger share
not equally O

17. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Covalent compounds
(Elemental) Composition ______________________________________
___________________________________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
(EN relatively small) nonmetal + nonmetal
OR metal + metal OR metalloid + any
enough atoms share enough electrons
so that each has the equivalent of a full outer shell
NO ions form / the stable unit is neutral

18. - + + - - + + - H H H H H O H H O H H O H H O H H O H bond ?
What if there were 2 atoms of O and 4 atoms of H ….
3 atoms of O and 6 atoms of H ….
4 atoms of O and 12 atoms of H …..
the is a discrete, stable unit of water called a _____________________
________________ do NOT _____________________________________ H H H H - +
H O H - +
for nonmetals
bonding to
nonmetals - +
H O H - +
H O H
H O H
bond ?
bond ?
are the + and - negative and positive enough to form a bond ?
the answer is ________
NO (stick yes, bond no)
H O H
molecule
molecules
chemically bond to other molecules

19. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Covalent compounds
(Elemental) Composition ______________________________________
___________________________________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
(EN relatively small) nonmetal + nonmetal
OR metal + metal OR metalloid + any
enough atoms share enough electrons
so that each has the equivalent of a full outer shell
for nonmetals
bonding to
nonmetals
form molecules
fixed number of atoms of each element
do not (chemically) bond to other molecules

20. - + - + - + H O H H O H H O H
Chemical formula for molecular substances
What is characteristic of molecules of substances ?
so, the chemical formula will represent
_______________________________________________________
the number of atoms of each element in a molecule
( a stable unit of the substance)
H O H - +
H O H - +
H O H - +

21. COMPOSITION, BONDING, STRUCTURE, and CHEMICAL FORMULAS
for Ionic and Covalent compounds
Covalent compounds
(Elemental) Composition ______________________________________
___________________________________________________________
Bonding __________________________________________________
_________________________________________________________
Structure _________________________________________________
Chemical Formula _________________________________________
(EN relatively small) nonmetal + nonmetal
OR metal + metal OR metalloid + any
enough atoms share enough electrons
so that each has the equivalent of a full outer shell
for nonmetals
bonding to
nonmetals
form molecules
fixed number of atoms of each element
do not (chemically) bond to other molecules
the number of atoms of each element
in a molecule (stable unit) of the substance

22. GUMDROPS