This document provides an overview of ionic and covalent bonding. It discusses the formation of ions through the loss or gain of valence electrons to achieve stable electron configurations. Ionic compounds are formed between metallic and nonmetallic elements and are held together by ionic bonds between cations and anions. Molecular compounds are formed by the sharing of valence electrons between nonmetallic elements to form covalent bonds. Polar and nonpolar covalent bonds are discussed based on differences in electronegativity between bonded atoms. Hydrogen bonds that occur between polar molecules like water are also summarized. Key terms related to ionic bonding, covalent bonding, and molecular structure are defined.

1. Chapter 7 and 8
Ionic and Covalent Bonding

2. 7.1 Ions
• Valence Electrons are the electrons in
the highest occupied energy level of an
element’s atoms.
• The number of valence electrons
determines the chemical properties of
an element.
• To find the number of valence electrons
in an atom of a representative element,
look at the group number. (see table
7.1)

4. Valence Electrons
• Valence electrons are usually the only
electrons used in chemical bonds, so they
are show in electron dot structures.
• In forming compounds, atoms tend to
achieve the electron configuration of a noble
gas.
• This is called the Octet Rule.
• All atoms want to have 8 electrons in their
outer or valence shell.

5. Formation of Cations
• Atoms of the metallic elements tend to lose
their valence shell electrons leaving 8 in the
next level down.
• An atom’s loss of valence of electrons
produces a cation, or positively charged ion.
• Remember, an ion is a charged atom that
has lost or gained electrons during the
chemical bonding process.

6. Neutral
Sodium Atom
+
Na
Whoa…I just
got smaller…

7. Neutral
Chlorine Atom
Cl
Now I’m bigger
and stronger….

9. Transition Metals
• For transition metals, the charges of
cations may vary.
• For example, elements such as
iron, nickel and copper may lose 1
to three electrons depending on the
chemical compound.

10. Formation of Anions
• A anion is an atom or group of atoms with a
negative charge.
• The gain of a negatively charged electron by
a neutral atom will create an anion.
• Non-metals typically form anions.
• The name of the anion is not the same as
the name of the atom.
• It usually ends in –ide. (See table 7.2)

12. Vocabulary Cards
• Valence electron
• Octet Rule
• Transition Metal

13. SUM IT UP
Name the
following ions
properly.
FClCa+2
O-2

14. Electron Configurations
• An electron configuration is a way to
show the electrons in a particular
atom in the proper order.
• Since electrons are arranged in
shells, each shell has a different
name.
• Use the periodic table to figure out
the electron configuration for any
atom.

16. LET’S PRACTICE!
1s 2s
2
1
1s 2s 2p
2
2
5
1s 2s 2p 3s 3p
2
10
3
4s 3d 4p
2
2
6
2
6

18. Vocabulary Cards
• Electron configuration

19. POST IT UP
What is the electron
configuration for carbon?
I S!
TH
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DH
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P!

20. 7.2 Ionic Bonds and Ionic
Compounds
• Compounds composed of cations and
anions are called ionic compounds.
• Ionic compounds are usually composed of a
a metal and other nonmetals.
• Although they are composed of ions, they
are electrically neutral…meaning no charges
or their charges cancel out.
• Bonds that hold ionic compounds together
are called ionic bonds.

22. Formula Units
• A chemical formula shows the kinds and
numbers of atoms in the smallest
representative unit of a substance.
• A formula unit is the lowest wholenumber ratio of ions in an ionic
compound.
• The chemical formula is not always the
lowest whole number ratio.

23. Let’s Practice
• How many kinds of atoms are in each of
these ionic compounds?
• NaCl
• MgCl2
• Ca(OH)2
• Ca3(PO4)2

24. Properties of Ionic Compounds
• Most ionic compounds are
crystalline solids at room
temperature.
• Ionic compounds generally have
high melting points.
• Ionic compounds can conduct an
electric current when melted or
dissolved in water.

25. Vocabulary Cards
• Ionic Bond
• Formula Unit

26. SUM IT UP
How many kinds of
each of these atoms
are in this
compound?
Ca (C2H6O2)2

27. 8.1 Molecular Compounds.
• Some compounds are not ionic.
• Instead of giving or taking electrons, these
compounds share electrons to complete their
Octet.
• This is called a covalent bond.
• A molecule is a neutral groups of atoms
joined by a covalent bond.
• A diatomic molecule is a molecule consisting
of only two atoms.
• A compound composed of molecules is
called a molecular compound.

28. Molecular Formulas
• A molecular formula is the chemical
formula of a molecular compound.
• It shows how many of each element
a molecule contains.
• A molecular formula does not tell
you about a molecule’s structure.

29. 8.2 The Nature of Covalent
Bonding
• In forming covalent bonds, electron
sharing usually occurs so that atoms
attain the electron configuration of a
noble gas.
• Combinations of nonmetallic elements
in groups 4A, 5A, 6A and 7A are likely
to form covalent bonds.
• They share electrons to achieve an
octet like a noble gas.

32. Diagrams
• An electron dot diagram represents the
shared pairs of electrons in a molecule.
• Each bond is two electrons or two dots.
• A structural formula represents the covalent
bonds by dashes and shows the
arrangement of the atoms.
• Each dash will equal two electrons.
• A pair of valence electrons not shared
between atoms is called an unshared pair,
lone pair or nonbonding pair.

33. Lone unshared
pairs

34. Polyatomic ions
• A polyatomic ion is a tightly bound
group of atoms that has a positive
or negative charge and behaves like
a unit.
• A group of atoms may be covalently
bonded as a polyatomic ion but
since the whole unit has a charge, it
can bond with other charged ions.

36. Vocabulary Cards
• Covalent bond
• Molecule
• Polyatomic ion
• Unshared pair

37. SUM IT UP
Draw the
structural
diagram for
water.

38. 8.4 Polar Bonds and Molecules
• Covalent bonds involve sharing between atoms.
• However, some atoms are more electronegative
than others meaning they tend to attract more
electrons than other atoms.
• When all the electrons are shared equally, it is a
nonpolar covalent bond.
• When one atom attracts electrons more strongely
than the other atom, a polar covalent bond forms.
• The atom that attracts more electrons become
slightly negative while the other becomes slightly
positive.
• This is NOT the same as an ionic bond with normal
charges!

40. Hydrogen Bonds
• Hydrogen bonds occur when a hydrogen that
is covalently bonded to another atom will be
weakly attracted to another atom on another
molecule.
• The partial positive charge of the hydrogen in
the polar molecule, gets attracted to the
partially negative charge on another
molecule.
• Water usually forms hydrogen bonds.
• As a result, life is possible.

42. Vocabulary Cards
• Polar molecule
• Hydrogen bond

43. POST IT UP
Why is water polar?
I S!
TH
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IN
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DH
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P!

44. Science Swag
Create an accurate model for a chemical
compound. Label the atoms and the bonds.
Bigger models with more atoms get more
points.