Download Ionic Bonding

On Your Best Behavior!
Q1
• There are two types of atoms:
Ionic Bonding
– Reactive - interact with other elements.
– Stable - Do not interact with other elements.
Which of these atoms is reactive?
Unit Essential Question:
How does atomic structure determine the chemical and physical
properties of matter?
What information can be gathered from the periodic table?
Presentation Objectives:
§ Define an ionic bond and ion.
§ Use Lewis structures to show how two elements ionically bond.
It’s Bonding Time!
Q2
• To become stable, form a chemical bond.
– A force that holds elements together.
• There are three main types of bonds that can form.
– Covalent bonds
• Atoms share valence electrons
A “happy atom” is an atom with a completed outer shell
Atoms prefer to have a completed outer shell.
Can I Have That?
Q3
• Atoms prefer to have a complete outer shell.
– One way to accomplish this goal is to form an
ionic bond.
• Bond that forms when one atom gives up valence
electrons and another takes them.
– Ionic bonds
• Atoms give up or take valence
electrons
– Metallic bonds
• All the atoms in the metal share the
valence electrons.
They become ions, which are atoms with a charge!
Q4
No Longer In Neutral Territory
• Atoms in the periodic table are neutral.
35
Br
– Number of protons equals the number of
electrons.
79.904
• When an atom has only one or two valence
electrons in its outer shell, it will give them away.
– There are less electrons than protons
• Let’s think about it mathematically…
35
– How many protons does Bromine (Br) have?
• Protons are positively charged.
Q5
What Happens When An Atom
Loses An Electron?
• Let’s say we have a sodium atom.
+ 35
– How many electrons does Bromine (Br) have? 35
P: 11
N: 12
Na
Atom of Sodium
Gives Away 1 VE
Protons: + 11
Protons: + 11
Electrons: - 11
Electrons: - 10
0
• Electrons are negatively charged. - 35
+1
Because it has a positive charge, we have a positive
ion, which is called a cation!
Adding them together: (+ 35) + (- 35) = 0
Is Sodium Stable When It Loses An
Electron?
Q6
What Happens When An Atom
Gains An Electron?
• When an atom has six or seven valence electrons
in its outer shell, it will take valence electrons.
P: 11
N: 12
– There are more electrons than protons
P: 11
N: 12
• Let’s say we have a chlorine atom.
Atom of Chlorine
Na
Na
+1
We leave the cation without electrons on the Lewis
structure to show that it has emptied its outer ring.
P: 17
N: 18
Cl
Protons: + 17
Electrons: - 17
0
Takes 1 VE
Protons: + 17
Electrons: - 18
-1
Because it has a negative charge, we have a negative
ion, which is called an anion!
Using Lewis Structures…
Q7
• In ionic bonding, it is easy to represent what is
happening using Lewis structures.
• What ionic compound forms when Calcium
(Ca) bonds with Fluorine (F)?
– Use arrows to show where the electron goes!
Na
Cl
Na+1 Cl
-1
F
Ca
• The atoms that tend to give away their electrons
are metals.
– The atoms that accept the electrons are nonmetals.
-1
F
-1
Formula: CaF2
Now you can write the formula of
NaCl
the resulting compound!
By convention, the cation is listed first!
Q9
+2
Ca F
F
• Once the atoms give or take the valence electrons
they become ions.
Metals and Nonmetals
Q8
Let’s Try Another One!
Q10
Neutral in the End
• When making ionic bonds, the ionic
compound is neutral.
– The charges of all the ions in the compound
must add up to zero.
+1
Na Cl
-1
(+1) + (-1) = 0
+2
Ca F
-1
F
-1
(+2) + (-1) + (-1) = 0
This should help you check your work…
Ionic bonds occur between a metal and a nonmetal.
If they don’t add up to zero, there is a mistake that must be fixed!