19
Notes 5-2: Ionic Bonds + - + -
Notes 5-2: Ionic Bonds
+
-
+
-
Chemical Bond
• A force of attraction that holds two atoms together
• Has a significant effect on chemical and physical properties of compounds
• involves the valence electrons
Valence Electrons – the electrons in the outermost energy level of an atom
+++
-
-
-
+++
+++
-
-
-
This Lithium Atom has one
valence electron
Carbon
4 valence electrons
Oxygen
6 valence electrons
Beryllium
2 valence electrons
Counting Valence Electrons
+
+++
+++ --
-
-
++
-
-
--
+
+
++
-
-
++
-
-
--
+
+
++
-
-
+
++
+
+++
+++
-
-
-
-
--
-
-+
How Many Valence Electrons?
• Hydrogen
• Lead
• Xenon
• Sulfur
• Rubidium
1 Valence Electron
4 Valence Electrons
8 Valence Electrons
6 Valence Electrons
1 Valence Electron
The Octet Rule
• Atoms will combine to form compounds in order to reach eight electrons in their outer energy level.– Atoms with less than 4 electrons tend to
lose electrons. (Usually metals)– Atoms with more than 4 electrons tend to
gain electrons. (Usually nonmetals)
• Be aware that there are some exceptions!
CONSIDER EIGHT A HAPPY NUMBER FOR ATOMS!
The Octet Rule In Action
Notice how the sodium atom has one valence electron. It is this electron that it will try to
get rid of according to the Octet Rule.
Notice how this chlorine atom has seven valence electrons,
one away from eight. It will try to gain one more according to
the Octet Rule.
++
+
+
+++
+++
-
-
-
-
--
-
-+
-
-
-
+
++
+
+++
+++
+++
-
-
-
-
--
-
-+
-
-
-
-
-
-
-
--
++
++ +
+
1
23
4
5
6 7
1
Where do you think Chlorine finds that one electron that it needs?
Lewis Structure(Electron Dot Diagram)
• a way of drawing the outer energy level electrons (valence) of an atom
• The symbol for the element surrounded by as many dots as there are electrons in its outer energy level (valence)
• Examples
How many valence electrons do each of these atoms have?
Mg:Magnesium
Al :.
Aluminum
N :.. .
Nitrogen
Oxidation Number
• The charge that an atom would have if it lost or gained electrons; ionic charge
• Can be helpful in determining which atoms will interact or bond with each other
• Example:
Mg:MagnesiumAccording to electron dot diagram for Magnesium,
it has two valence electrons. Because Magnesium is “unhappy” with two, it will typically lose them. If this happens it will turn into a Magnesium ion. At this point it will have an oxidation number of
+2. Mg2+
What Could the Oxidation Number Be?
H O
Ne Sr
+1 or -1 because it can gain or lose one electron
-2 because it will gain two electrons
0 because it will notgain or lose electrons
+2 because it will lose two electrons
3 Types of Chemical Bonds
•Ionic•Covalent•Metallic
Which different groups or families
of elements will most-likely
interact to create these
typesof bonds?
IONIC BONDS
-
+
++
+
+++
+++
-
-
-
-
--
-
-+
-
-
-
-
-
-
-
-
-
• The force of attraction between oppositely charged ions.• Complete transfer of electrons• Usually form between atoms of metals and atoms of non-
metals• Resulting compounds have a name that usually ends in –ide
Example - Sodium Chloride (NaCl)
Cl Na1- 1+
+
++
+
+++
+++
-
-
-
-
--
-
-+
-
-
IONIC BONDING
When an atom of a nonmetal takes one or more electrons from an atom of a metal so both
atoms end up with eight valence electrons
IONIC BONDING
IS THE COMPOUND AN IONIC COMPOUND?
METALMETAL NONMETAL
SUBSCRIPTS
IONIC BOND FORMATION
Neutral atoms come near each other. Electron(s) are transferred from the Metal atom to the Non-metal atom. They stick together because of electrostatic forces, like magnets.
POLYATOMIC IONS--a group of atoms that act like one ion
--usually end in “ate” or “ite”
NH4+1—ammonium ion
CO3-2--carbonate ion
PO4-3--phosphate ion
IONIC BONDING
IONIC BONDING
SODIUM SULFATE
Groups Per 1B
• Group 1) Corinne, Melissa, Vanessa, Nik, Zane, Arun
• Group 2) Brian, Macy, Aaron, Cole, Jingjing, Elise
• Group 3) Vanessa, Gina, Jorge, Genesis, Stephen, Victor
• Group 4) Brock, Michael, Jack, Brent, Maty, Anthony
• Group 5) Sophia, Sorayah, Justin, Jazmin, Jackie, Faith
• Group 6) Emily, Isabella, Sophie, Joe, Cheyenne
Groups Per 2B
• Group 1) Chrystian, James, Alissa, Brody, Drew, Victor
• Group 2) Jason, Garrison, Ian, Jonathan, Zach C, Leslie
• Group 3) Rachel, Naysha, Fabiola, David, Jarrett, Zach M
• Group 4) Jake, Amanda, Juliette, Kayleigh, Neal, Andrea
• Group 5) Horacio, Evelyn, Ryan, Sarina, Abby, Andrew M
• Group 6) Josh, Holly, Sara, Megan, Lawton
Groups Per 3B
• Group 1) Luke, Hector, Chris, Francisco, Carla, Nesly
• Group 2) AJS, CJ, Grace, Molly, Emma, Robert
• Group 3) Sammy, Michael, Will, Katia, David, Cole
• Group 4) Sanjana, Ava, Hanna, Kyle, Austin, Lacey
• Group 5) Zach, Eric, Julia, Megan, Monetha
• Group 6) Emily, Kylie, Hope, Saabir, Ariana, Natalie
