Ionic Bonding
Content Objectives
• SWBAT describe the process of ionic bonding
due to some atoms removing electrons from
other atoms to reach the Octet Rule and then
attracting to each other due to electrostatic
charger.
Valence Electrons
• Valence electrons are the electrons in the
outermost s- and p-orbitals that can be
involved in chemical reactions.
1s orbital is not involved
Valence Electrons
• Valence electrons are the electrons in the
outermost s and p-orbitals that can be
involved in chemical reactions.
1s orbital is not involved
Outer octet of 2s and 2p orbitals are involved
Ions
Cation
Positively Charged Atom
(loses electrons)
Pronounced CAT-ion
K+1
Ions
Cation
Positively Charged Atom
(loses electrons)
K+1
Anion
Negatively Charged Atom
(gains electrons)
Cl-1
Pronounced AN-ion
Ions
Cation
Positively Charged Atom
(loses electrons)
K+1
Anion
Negatively Charged Atom
(gains electrons)
Cl-1
Ionic Bonding occurs when a cation gives electrons to an anion
and the atoms become attracted to each other due to the
opposite charges.
:
Ionic Bonds
· Cl :
:
Na·
• Sodium has one valence electron it wants to lose
• Chlorine has 7 valence electrons, so it wants to
gain one more to make it to eight.
:
Ionic Bonds
· Cl :
:
Na·
• The Sodium atom donates its one
valence electron to Chlorine.
· Cl-1:
·
:
+1
Na
:
Ionic Bonds
• This means Na has the electron configuration of the
noble gas before it, which is Neon
• Sodium’s electron configuration is now written as [Ne]+
· Cl-1:
·
:
+1
Na
:
Ionic Bonds
• Chlorine now has the electron configuration of the noble
gas after it, which is Argon.
• Chlorine’s electron configuration is now written as [Ar]-
:
Ionic Bonds
:
Na : Cl :
• Sodium and Chloride are now ionically bonded
to form a new compound known as sodium
chloride (NaCl).
• This is known to most of us as Table Salt.
Ionic Bonds
-1
: :
+1
Na : Cl :
• Now each sodium is positively charged and
each chlorine is negatively charged.
• They are attached because opposite charges
attract electrostatically.
• However, together they balance each other out.
Ionic Bonds
+1
: :
-1
: Cl :
-1
: :
+1
Na : Cl :
Na
• But, the positive charge, does attract other
negatively charged molecules, such as other
chlorine ions
• The same holds true for negatively charged
chlorine ions attracting other positive ones
+1
-1
: :
Na
-1
: :
+1
+1
: Cl : Na : Cl : Na
• Soon, they all begin to line up
: :
Ionic Bonds
: Cl :
Ionic Bonds
-1
+1
-1
: :
+1
: :
: Cl :
+1 -1
: :
: :
-1
Na : Cl : Na : Cl : Na : Cl :
• Soon, they all begin to line up
• This then forms crystals of salt
+1
Na
Ionic Bonds
-1
+1
-1
: :
+1
: :
+1 -1
: :
: :
-1
+1
: Cl :Na : Cl : Na : Cl : Na : Cl :Na
• Soon, they all begin to line up
• This then forms crystals of salt
Ionic Bonds
• Bonding that involves a transfer of electrons.
• Positively and negatively charged atoms (ions)
result from this transfer
• The resulting positive and negative charged
atoms are “attracted” to each because of their
opposite charges.
Na+
Cl-
Solvents and Solutions
• Because ionic molecules have positive and
negative atoms, they can be pulled apart by other
substance with positive and negative charges.
Solvents and Solutions
• One example is dissolving salt into water
• Water molecules have positive ends near the
hydrogens and negative ends near the oxygen.
Solutions
• Since all of the ions are evenly dispersed and
dissolved in the water, it makes a solution of
salt water.
• This solution is transparent.
Reforming Crystals
• When the water evaporates, the positive Na
ions and the negative Cl ions come back
together again!
So, Who Makes Ions Anyways?
• It all depends on how many valence electrons
they have and what they need to get to noble
gas configuration.
Question #1: How many valence electrons does
Aluminum have?
So, Who Makes Ions Anyways?
• It all depends on how many valence electrons
they have and what they need to get to noble
gas configuration.
Question #1: How many valence electrons does
Aluminum have?
Answer: 3
Question #2: What ionic charge will it have to become
noble gas configuration?
So, Who Makes Ions Anyways?
• It all depends on how many valence electrons
they have and what they need to get to noble
gas configuration.
Question #1: How many valence electrons does
Aluminum have?
Answer: 3
Question #2: What ionic charge will it have to become
noble gas configuration?
Answer: Al+3
Alkali Metals
Charge: +1
Alkaline Earth Metals
Charge: +2
Boron Family
Charge: +3
Carbon Family
Do not usually make ions, but could be +4 or -4
Nitrogen Family
Charge: -3
Oxygen Family
Charge: -2
Halogens
Charge: -1
Noble Gas Family
Do not make ions, because they already have full orbitals
Transition Metals
A variety of positive ions from +1 to +7
We’ll discuss these in more detail later
Polyatomic Ion
• Polyatomic ions are ions that have multiple
atoms attached to each other, but as a unit
have a net charge.
• Sulfate (SO4-2) is an example.
Polyatomic Ions
Anions
Cations
Acetate
CH3COO−
Ammonium
NH4+
Bicarbonate (hydrogen carbonate)
HCO3-
Hydronium
H3O+
Carbonate
CO3-2
Mercury(I)
Hg2+2
Cyanide
CN−
Hydroxide
OH−
Nitrate
NO3-
Phosphate
PO4-3
Sulfate
SO4-2
Sulfite
SO3-2
State
−1
+1
Anion name
chloride
Formula
Cl−
Structure
Polyatomic Cations are more rare
+3
+5
+7
hypochlorite chlorite
chlorate
perchlorate
ClO−
ClO3−
ClO4−
ClO2−
Acetic Acid Dissolving in Water
Acetic Acid
Water
Acetate ion
Hydronium ion
+
Content Objectives
• SWBAT describe the process of ionic bonding
due to some atoms removing electrons from
other atoms to reach the Octet Rule and then
attracting to each other due to electrostatic
charger.