electrons and chemical bonding spring 2013 day 2
TRANSCRIPT
You Will Need:1. Pencil, Text Book- Periodic Table,
Colored Pencils2. Ionic & Covalent Bonding 1 pages-2
sides (pgs 5 & 6 of packet)4. Log #3 Update5. Building Blocks of Matter –
Counting Atoms– Due NOW
Question #18 & 24
1. Disregard- corrected incorrectly
• Added 4 points to total score
2. Answer Key was from a different version of the test.
Please SCHEDULE:
1. To take Retake Test #2
• 129/185 or lower
2. Starts Thursday of this week
3. Parent Signature and Corrections – due Wed.
You will need 100 3 x 5 cards
1. Print out Questions & Answers hyperlinked on Learning Point
• Glue, Staple or Tape Questions on the Front and Answers on the back
OR
• You can write out the questions & answers
2. Due at the beginning of class on Friday
3. Quiz on Friday
1. The class of elements found along the zig-sag line….
2. The charge of the nucleus of any atom….Why?
3. The scientist who developed the First Atomic Theory?
4. The MOST reactive NONMETALS on the Periodic Table are the ______________.
5. Is Aluminum more likely to give or take electrons? Why?
6. When two charged atoms bond they form this type of bond.
7. What does “COVALENT” mean?8. Which class of elements tend to
GAIN electrons?9. What is the valence of Sulfur?
How do you know?10. How many more electron bonds
would Sulfur need to have a full outer shell?
Timer Designers: In charge of today’s lesson on the computer (R & R Required)
Everything on this planet is made of atoms from elements. Even though the number of elements on the Periodic Table is limited, joining the elements in different ways allows you to make a huge number of combinations.
Chemical Bonding is the joining of atoms to form new
substances. The properties of these new substances are different from the properties of the original elements. When chemical bonds form, electrons are shared, gained or lost.
Everything on this planet is made of atoms from elements. Even though the number of elements on the Periodic Table is limited, joining the elements in different ways allows you to make a huge number of combinations.
Chemical Bonding is the joining of atoms to form new
substances. The properties of these new substances are different from the properties of the original elements. When chemical bonds form, electrons are shared, gained or lost.
Understanding the electron configuration, (Electron Dot,) for each
atom will help you understand how different elements will bond or not bond with other elements.
Need to Know!
Not all the electrons in an atom are used to make chemical bonds. It is the electrons on Outer-Most Level or VALENCE electrons, (Electron-Dot) that determine how an atom will react (bond). REMEMBER: You can use your periodic table to determine valence values for most elements.
Atoms want to be “happy” or stable….if they have a
full outer shell. Atoms that have fewer than eight valence electrons usually form bonds. The only time a full shell is equal to 2 if for the element Helium.
Element Bohr Model Lewis Dot (Symbol + Valence)
Lithium
Atomic #
Atomic Mass – Atomic #
Neon
Atomic #
Atomic Mass – Atomic #
Row =
Electrons= Protons =
Neutrons =
2
3-3+
7-3=
4
P = 3N = 4
21
Li
Row =
Electrons= Protons =
Neutrons =
P =10N =10 Ne
2
10-10+
20-10
10
28
valence
valence
Element Group Valence Bond or Not Bond
Hydrogen 1 1 Bond
Magnesium
Oxygen
Sulfur
Krypton
Lithium
Carbon
Compound Lewis Dot Bonding Config. Type of Bond and Why?
Sodium Fluoride (NaF)
Diatomic Fluoride (F2)
Hydrogen Fluoride (HF)
Watch the video clip on Covalent & Ionic Bonding (hyperlinked on Learning Point)
Question Answer
Ion • Charged atom• Caused by a transfer (lose or gain) or shared
electron
What are the characteristics of Ionic Bonds?
• Usually between Metals and Nonmetals• Transfer of electrons – atoms become IONS• Form Crystal Lattices• Brittle• High melting and boiling points• Dissolve easily in water• Form compounds• Specific shape
Bismut
h
Crystal Lattice
Question Answer
What are the characteristics of Ionic Bonds?
• Usually between Metals and Nonmetals• Transfer of electrons – atoms become IONS• Form Crystal Lattices• Brittle• High melting and boiling points• Dissolve easily in water• Form compounds• Specific shape
Illustrate a neutrally charged Bohr Model of an aluminum atom.
Before you move to the next slide….try to draw this on your own and then check to see how you did.
If you made a mistake….figure out what you did incorrectly.
Question Answer
What are the characteristics of Ionic Bonds?
• Usually between Metals and Nonmetals• Transfer of electrons – atoms become IONS• Form Crystal Lattices• Brittle• High melting and boiling points• Dissolve easily in water• Form compounds• Specific shape
Illustrate a neutrally charged Bohr Model of an aluminum atom.
P=13N=14
2 83
Question Answer
Illustrate a positively charged Bohr Model of an aluminum atom. (3+)
Before you move onto the next slide….try to draw this on your own.
Question Answer
Illustrate a positively charged Bohr Model of an aluminum atom. (3+)
Why is Al3+ considered an ion?
(Look at all the subatomic particles before you answer this question.)
P=13N=14
28
Forming Sodium Chloridehttp://www.youtube.com/watch?v=2mzDwgyk6QM
Before (pg. 233) After
Questions:1)Why does Sodium become an Ion? 2)Is it Positive or Negative? Why?3)Why does Chlorine become an Ion? 4)Is it Positive or Negative? Why?
Questions:1)Why do Sodium and Chlorine bond?2)What is the overall charge of the compound?3)Does NaCl have the same characteristics as Na and Cl?4)What are some unique characteristics of NaCl?
Question Answer
Characteristics of Covalent bonds • Valance electrons are shared• More often between nonmetal• Low melting and boiling point• Free flowing but can be brittle• Form molecules• Do not have a specific shape - flexible
View Video – Covalent Bonding – hyperlinked on Learning Point.http://www.youtube.com/watch?v=1wpDicW_MQQ
How many types of covalent bonds are shown in the video clip? ______
C6H10O5
C12H22O11
Molecule Illustration Explanation Electron Dot (Color Code each element)
1. What kind of bond does Hydrogen & Oxygen make?
2. How do you know?3. Why does one Oxygen
bond with two Hydrogen atoms?
http://www.youtube.com/watch?v=ulyopnxjAZ8&feature=relmfu Drawing Lewis Dot Diagram Bonds
P=8N=8
P=1N=0
P=1N=0
Element Bohr Model Lewis Dot (Symbol + Valence)
Lithium
Atomic #
Atomic Mass – Atomic #
Neon
Atomic #
Atomic Mass – Atomic #
Row =
Electrons= Protons =
Neutrons =
2
3-3+
7-3=
4
P = 3N = 4
21
Li
Row =
Electrons= Protons =
Neutrons =
P =10N =10 Ne
10
10-10+
20-10
10
28
P=8N=8
P=1N=0
P=1N=0
How do we determine the type of bond in a compound?
• Identify class of elements• Same class usually covalent• Opposite class usually ionic
• Calculate the electronegativity factor
What is ELECTRONEGATIVITY? A measure of how much an element wants an electron
How do you know the electronegativity factor of an element?
Look it up (see next slide)
What are the determining values for each type of bond?
0-0.4 = Non-polar covalent
.41-2.0 = Polar covalent
>2.0 = Ionic
http://www.youtube.com/watch?v=7DjsD7Hcd9U
http://www.tutor-homework.com/Chemistry_Help/electronegativity_table/electronegativity.html
ELECTRONEGATIVITY VALUES
0-0.4 = Non-polar covalent.41-2.0 = Polar covalent>2.0 = Ionic
Let’s try a couple:
P=8N=8
P=1N=0
P=1N=0
H2OCalculate the electronegativity factor
H = 2.2O = 3.44
3.44 – 2.2 = 1.24
NaCl
0-0.4 = Non-polar covalent.41-2.0 = Polar covalent
>2.0 = Ionic
Polar Covalent
Ionic
Na = .93Cl = 3.16
3.16 - .93 = 2.23
Homework:
1)Building Blocks of Matter – Counting Atoms – Due Tomorrow
2)Test #2 Corrections and Signature – Due Wednesday
3)Ionic and Covalent Bonding – Due Thursday
4)STAR Cards #1-30 – on 3x5 cards – Due Friday at the beginning of class