1. Charge Those Particles Part I: “Getting Charged”

2. Questions and Review of the Read
What is an ion?
What is a dipole?
How do they get charged?
If they are composed of charged particles how can they be neutral?
Is when an entire molecule or atom is charged
When a section of a molecule is charged positive on one part and negative on another
They are composed of electrons and protons
Equal amounts of positive and negative charges (net charge or the sum of charges = 0)

3. Questions and Review of the Read
How many protons and electrons does Na have?
What about a Sodium ION?
Na= Protons 11, electrons 11 (if neutral)
Na 1+ has one more positive charge than it does a negative charge. The extra positive charge makes the whole atom charged.
Protons = 11 (can the number of protons change?)
Electrons = 10
Na 0 Na1+ + e-
11e-
11p+
10e-
+ e-

4. Questions and Review of the Read
How many protons and electrons does Cl have?
What about a Chloride ION?
Cl= Protons 17 electrons 17 (if neutral)
Cl -1 has one more negative charge than it does a positive charge. The extra negative charge makes the whole atom charged.
Protons = 17 (can the number of protons change?)
Electrons = 18
Bohr Model?????

5. Questions and Review of the Read
How many protons and electrons does Ca have?
What about a Calcium ION?
Ca= Protons 20 electrons 20(if neutral)
Ca 2+ has two more positive charges than it does a negative charges. The two extra positive charge makes the whole atom charged.
Protons = 20 (can the number of protons change?)
Electrons = 18
Bohr Model?????

6. Stop and Think Part 1
1. If you touch a charged object, what might happen?
Static shock?
Remember also that charged particles move from a area of high concentration to an area of low concentration, such as your hand.
Or maybe a if a hand is charged then it will transfer to the object.

7. Stop and Think Part 1
2. Is a crystal of solid sodium chloride positive, negative, or neutral? Explain your answer based on everyday experiences.
We know that salt (sodium chloride in a solid crystal lattice) is neutral because we’ve never been shocked by salt.

8. Stop and Think Part 1
3. Sketch a microscopic view of a water solution that contains dissolved sodium chloride. In the caption below your sketch, explain the number of positive and negative ions that you have. + -
Solid NaCl
There are equal amounts of positive and negative ions in NaCl. The solution is neutral. + -
Cl -1
Na +1

9. Stop and Think Part 1
4. Repeat question 3 for a solution with magnesium chloride, MgCl2 ++
Solid MgCl2 -
MgCl2 dissolves in water to produce twice as many negative particles as positive. The net charge is still zero since Mg particles are 2+ -
Cl 1-
Mg 2+ ++

10. Stop and Think Part 1
5.Use chemical symbols to show the following processes.
A neutral potassium atom becoming a 1+ potassium ion
A neutral calcium atom becoming a 2+ calcium ion
A neutral fluorine atom becoming a 1- fluoride ion
A natural Oxygen atom becoming a 2- oxide ion
K0 K+1 +1e-
Ca Ca+2 +2e-
F 0 +1e F-1
O 0 +2e O-2

11. Charge Those Particles Part II: “Ionization vs. Dissociation”

12. Ionization versus Dissociation
Energy is required to remove a negative charge from a positive charge. (because you need energy to overcome the force of attraction, opposites attract).
Ionization: the process of removing an electron from an atom (i.e., separating positive and negative charges)
Na 0 + IE Na1+ + e-
Forming a sodium ion from a neutral Na atom requires energy. The electron on the right can transfer to another particle
11e-
11p+
10e-
+ e-
+ IE

13. Ionization versus Dissociation
Dissociation: the process of separating positive and negative ions from a crystal lattice. (i.e., separating positive and negative charges)
NaCl(s) Na 1+(aq) + Cl- (aq)
Symbol representation of dissociation. Sodium chloride (solid NaCl) dissociates in water to form sodium ions (Na+) and Chloride (Cl-) in an aqueous solution.

14. Ionization versus Dissociation
Ionization and Dissociation are both processes where positive and negative charges are being separated.
What’s the difference???
Ionization: forces WITHIN the particle
Separation of protons and electrons
Dissociation: forces BETWEEN particles
When the ions are separated in the crystal lattice
What’s the crystal lattice?

15. Ionization versus Dissociation
Ionization Dissociation + -
Depends on forces inside an atom (between electrons and protons)
Ionization energy is the energy required to remove an electron from a neutral atom
Depends on forces between atoms (between positive and negative ions)
Occurs because of solvation.
Ions separate in solution

16. Trends in Ionization Energy
Ionization Energy Increases
Highest I.E.
Ionization Energy Decreases
Lowest I.E.

17. Ionization versus Dissociation
Ionization energy is like “electron greed”.
How badly does the atom what to hold on to its electron?
Lower I.E. means it is easier (takes less energy) to remove an electron from the atom and create an ion.
Higher I.E. means it is more difficult (takes more energy) to remove and electron from the atom and create an ion.

18. Ionization versus Dissociation
P&P #4: Make a Venn diagram to illustrate the similarities and differences between ionization and dissociation.

19. P&P #4 p. 130

20. Ionization versus Dissociation
Ionization energy can help us to predict the type of bond that will form between two atoms.
HOW???
Bond type depends on differences in electrical properties. Let’s try to find a trend…

21. Ionization versus Dissociation
P&P #5a: Predict the relative ionization energies associated with ionic, covalent, and polar bonds.
Ionic bonds form when particles have opposite net charges (IE energy is High)
Example: Na + + Cl –
One particle loses an electron
Which one?
The ionization energies of 2 atoms in an Ionic solid are very far apart (just like their location on the Periodic Table)

22. Ionization versus Dissociation
P&P #5a: Predict the relative ionization energies associated with ionic, covalent, and polar bonds.
Covalent bonds have the same tendency to attract electrons so they act more neutral (IE energy is low)
Example: CO2
Why?
The atoms involved in bond have the same tendency to attract electrons
Look at the locations of Carbon and Oxygen
Polar bonds are between ionic and covalent
H20

23. Ionization versus Dissociation
P&P #5b: Predict what type of bonding (Covalent, ionic, or polar) occurs between hydrogen atoms in the elemental compound H2
Hydrogen gas has two atoms that are the same.
Ionization energies are equal
If the energy is equal, than any electrons involved in bonding will be shared equally= COVEALNET

24. Ionization versus Dissociation
P&P #5c: Draw a series of molecular level sketches to show whether hydrogen gas H2 is highly soluble in water. H H O
No dipole H H
No interaction
Hydrogen gas (H2) molecule interacting with water. Hydrogen’s low solubility in water is due to hydrogen being non-polar and water being polar

25. Charge Those Particles Part III: “Sharing Electrons”

26. Electronegativity
Covalent bonds form when atoms have similar electrical properties.
Ionization energy is one way to quantify those electrical properties
Electronegativity is another way to quantify electrical properties.

27. Electronegativity
Electronegativity is the ability of an atom to attract electrons.
The higher the electronegativity, the more strength the atom has to pull electrons toward itself.

28. Electronegativity
Electronegativity is the ability of an atom to attract electrons.
The electronegativity scale was devised by Linus Pauling.
It is an arbitrary scale with Fluorine (the most electronegative element) having a value of 4.
All other electronegativities are assigned relative to Fluorine.
Why Fluorine??

29. Electronegativity
Differences in electronegativity between two atoms can tell you what type of bond will form between those atoms.
If two atoms have similar electronegativities, neither is stronger than the other. They will share electrons equally… this is a covalent bond.

30. Electronegativity
If two atoms have somewhat different electronegativities, one atom is slightly stronger than the other. They will share electrons UNequally… this is a polar covalent bond.
They are still sharing electrons, but the electrons spend more time around the more electronegative atom (giving it a slight negative charge), and less time around the less electronegative atom (giving it a slight positive charge) creating a dipole.

31. Electronegativity
If two atoms have very different electronegativities, one atom is much stronger than the other. The stronger atom will take the electron(s) from the other atom. This is an ionic bond.
The atom that takes the electron(s) becomes a negative ion.
The atom that gives up the electron(s) becomes a positive ion.
The ions are attracted to each other and form a crystal lattice.

32. Predicting types of bonds…
Type of bond
Non-polar covalent
Polar covalent
ionic
Electronegativity difference
< 0.4
0.4 – 2.1
> 2.1
Electrons
Shared Equally
Shared Unequally
Transferred (not shared)
Example
O2 or H2 or CO2
H2O
NaCl
Terms
Covalent molecule
Polar molecule (with a dipole)
Ionic compound (i.e., salts)

33. Electronegativity What trends do you see in electronegativity?
What type of bonds form when atoms from opposite sides of the periodic table for a compound?

34. Trends in Electronegativity
Electronegativity Increases
Highest EN.
Electronegativity Increases
Lowest EN.

35. Questions
P&P #1 p. 131: Make a Venn diagram to compare and contrast Ionization and Electronegativity
P&P #3a p. 134: Make a diagram to show how each pair of atoms listed below shares or transfers electrons and determine the type of bond:
Hydrogen – Oxygen in water
Carbon – Oxygen in CO2
Potassium – fluorine in KF
Carbon – Hydrogen in CH4
Bromine – Bromine in Br2

36. P&P #3 H-O bond in water H20 C-O bond in Carbon dioxide K-F bond in KF
1.4 Polar Covalent O H
Electrons closer to Oxygen
Electrons closer to Oxygen
O 3.5
C 2.5
1.4 Polar Covalent O C O
F 4.0
K .8
3.2 Ionic K F
Electrons closer to Fluorine

37. P&P #3 C-H bond in methane CH4 Br-Br bond in Bromine C C 2.5 H 2.1
.4 Covalent H
Electrons almost in the middle
Br 2.8
0 Covalent Br Br
Electrons are in the middle

38. Venn Diagram
Electronegativity is the tendency of an atom to ATTRACT electrons in a bond
Both have tendencies to want electrons
Same trends in the periodic table
Ionization is the energy needed to REMOVE an electron

39. Reflect and Connect
1. Predict what type of molecule (or compound) each of the following might be, justify:
A) CaCl2
B) N2
C) CO2
2. Describe in your own words how bonding atoms contributes to the characteristics of an entire molecule or group of atoms.

40. Reflect and Connect
Predict what type of molecule (or compound) each of the following might be, justify:
A) CaCl2
B) N2
C) CO2
CaCl2 is ionic, this is because Ca and Cl are on opposite ends of the Periodic Table.
Ca carries a positive charge
Cl carries a negative charge
N2 is covalent because they have the same electronegativity, ionization energy, and are the same element
CO2 is covalent because they have the similar ionization energies and are near each other in the Periodic Table

41. Reflect and Connect
2. Describe in your own words how bonding atoms contributes to the characteristics of an entire molecule or group of atoms.
Bonding inside a molecule affects the entire molecule because bonds effectively distribute charge that charge in the molecule.

42. Balance Chemical Equations Review
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43. Review Videos
Bohr:
Ionization:
Electronegativity:
Covalent Bonding:
Polar:
Ionic: EOy2mw&feature=youtu.be