Chemistry
Matter and Change
Chapter 7
Ionic Compounds and Metals
Previous
Ca: 1s22s22p63s23p64s2
Ar: 1s22s22p63s23p6
Draw the valence shell diagrams.
Ca is what element?
Ar is what element?
Compare Ca to Ar:
Previous
Ca: 1s22s22p63s23p64s2
Ar: 1s22s22p63s23p6
Cl: 1s22s22p63s23p5
What element is Cl? Draw its valence shell
diagram.
Compare Cl to Ar:
Previous
Ca: 1s22s22p63s23p64s2
Ar: 1s22s22p63s23p6
Cl: 1s22s22p63s23p5
What will it take for calcium and chlorine to
be like argon?
Why would calcuim and chlorine want to be
like argon?
Previous
K: 1s22s22p63s23p64s1
Ar: 1s22s22p63s23p6
Draw the valence shell diagrams.
What element is K?
Compare and contrast:
Why is argon stable?
How can K become “Noble Gas” like?
Previous
Ca: 1s22s22p63s23p64s2
Ga: 1s22s22p63s23p64s23d104p1
What element is Ga? Draw its valence shell
diagram.
Compare and contrast:
Important
“Noble Gas Like” means to have a full octet
of valence electrons in the s and p orbitals.
The atoms do not become Noble Gases.
Only the atomic number determines the
name of the element. The only way to
change to another element is nuclear
decay, remember the proton and neutrons
are in the nucleus not the electrons.
7.1 Ion Formation
How do so many compounds form from the
relatively few elements know to exist?
Chemical Bond
A chemical bond is the force that holds two
atoms together.
One way is an attraction between the
electron (-) on one atom and the nucleus
of another (+).
Another way is the attraction between ions.
Valence Electrons
Electrons in the s and p orbitals only
Gp 1
2
13
14
15
16
17
18



 


Li Be B  C  N  O    

Ne
Fe



 




Cation
Positively charged atom
Lose 1 or more electrons
Groups 1, 2 and 13
Group 1
Li: 1s22s1 or [He] 2s1
The outermost shell has 1 electron.
Remove 1 electron and lithium is like the
Noble Gas helium, called lithium cation
1+
Li
Group 1
Na: 1s22s22p63s1 or [Ne]3s1
The outermost shell has 1 electron.
Remove 1 electron and sodium is like the
Noble Gas neon, called sodium cation
1+
Na
Group 1
K: 1s22s22p63s23p64s1 or [Ar]4s1
The outermost shell has 1 electron.
Remove 1 electron and potassium is like the
Noble Gas argon, called potassium cation
1+
K
Group 2
Be: 1s22s2 or [He] 2s2
The outermost shell has 2 electrons.
Remove 2 electrons and berryllium is like
the Noble Gas helium
2+
Be
Group 2
Mg: 1s22s22p63s2 or [Ne]3s2
The outermost shell has 2 electrons.
Remove 2 electrons and magnesium is like
the Noble Gas neon
2+
Mg
Group 2
Write the Noble Gas electron configuration
for Ca
Write the ion symbol.
Group 13
B: 1s22s2sp1 or [He] 2s22p1
The outer most shell has 3 electrons.
Remove 3 electrons and boron is like the
Noble Gas helium
3+
B
Group 13
Write the Noble Gas electron configurations
for:
Al
Ga
Write the ion symbols.
Cations
Does removal of an electron from a neutral
atom require or release energy?
Formation of a Cation
Notice
Requires
Energy
Notice
Smaller Cloud
Why?
Notice
“free” electron
Metals
• Group 1 and 2 most reactive
• Form cations easy
Transition Metals
Have full s2 orbitals
Lose these 2 electrons and maybe one
electron in the d orbital
Sometimes it is difficult to predict how many
Important to write cation symbol
2+
Fe
and
3+
Fe
Anion
Negatively Charged Ion
Gain one or more electrons
Name is changed: __ine becomes __ide
chlorine  chloride
nitrogen  nitride
Group 17
Flourine wants to be neon like.
Has 7 valence electrons and wants 8
Gains 1 electron and has a -1 charge
Flouride
F
Group 17
Chlorine wants to be argon like.
Has 7 valence electrons and wants 8
Gains 1 electron and has a -1 charge
Chloride
Cl
Group 17
Bromine wants to be krypton like.
Has 7 valence electrons and wants 8
Gains 1 electron and has a -1 charge
Bromide Br
-
Group 16
Oxygen wants to be neon like
Has 6 valence electrons and wants 8
Gains 2 electron and has a -2 charge
Oxide
2O
Group 16
Sulfur wants to be argon like
Has 6 valence electrons and wants 8
Gains 2 electron and has a -2 charge
Sulfide
2S
Group 16
Write the Valance Electron Diagram for
Selinium, Se
What noble gas does it want to be like?
How many electrons does it need?
Write the name and symbol for the anion.
Group 15
Find the number of valence electrons.
What noble gas do these elements want to
be like?
Draw the electron dot structure for each.
Name the anion and write its name.
Nitrogen, Phosphorus and Arsenic
Formation of an Anion
Notice
“free’ electron
mol
Notice
Smaller cloud
Now
Larger cloud
Notice
Energy
Released
Compare
How do the energy changes accompanying
positive ion and negative ion formation
compare?
Questions p. 209
1. Compare the stability of a lithium atom
with that of its ion, Li+.
2. Describe two causes of the force of
attraction in a chemical bond.
3. Why are all of the elements in group 18
unreactive, whereas those in group 17
are very reactive?
4. Summarize ionic bond formation by
correctly paring these terms: cation,
anion, electron gain, electron loss.
5. Write out the electron configuration for
each atom. Then predict the change that
must occur in each to achieve a noblegas configuration.
a. nitrogen b. sulfur c. barium d. lithium
6. Draw models to represent the formation
of the positive calcium ion and the
negative bromide ion.
Fluorine
1.
2.
3.
4.
Write out electron configuration
Calculate number of valence electrons
What ion forms? (symbol)
What is the name of the ion?
Each Student
Write 5 element symbols on a piece of paper
with atomic number 54 or lower.
Switch papers
Write electron configuration for each
element
Draw electron dot diagram
Determine what type of ion is most likely
formed
Exit Ticket
Determine the ions formed for
Strontium
Aluminum
Sulfur