Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation...

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Periodic Trends Periodic Trends

Transcript of Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation...

Page 1: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Periodic TrendsPeriodic Trends

Page 2: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Atomic RadiusAtomic Radius Ionic RadiusIonic RadiusOxidation NumberOxidation NumberElectronegativityElectronegativity Ionization EnergyIonization EnergyElectron AffinityElectron Affinity

All of these characteristics can be predicted All of these characteristics can be predicted by the atoms electron configurationby the atoms electron configuration

Page 3: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Atomic RadiusAtomic Radius

the distance from the center of an atom’s the distance from the center of an atom’s nucleus to the outermost electronnucleus to the outermost electron

Measured using two atoms, why?Measured using two atoms, why?

Distance between distance halfway Distance between distance halfway between two adjacent nuclei in a covalent between two adjacent nuclei in a covalent bond.bond.

Page 4: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.
Page 5: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.
Page 6: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.
Page 7: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

As we saw in our graphing activity and the As we saw in our graphing activity and the previous diagrams the atomic radius…previous diagrams the atomic radius…

Decreases going across a period Decreases going across a period

Increases going down a groupIncreases going down a group

But why??? But why???

Page 8: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Take a look at the electron configurationsTake a look at the electron configurationsWhen you go across a period what happens?When you go across a period what happens?

Your not increasing your E-level, however Your not increasing your E-level, however your increasing your neg. chargeyour increasing your neg. charge

4

e-

e-

e-

e-

8e-

e-

e-

e-

e-

e-

e-

e-

Page 9: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

As you increase the neg. charge the As you increase the neg. charge the attraction between the E-level and the attraction between the E-level and the nucleus increases, pulling the E-level in nucleus increases, pulling the E-level in closer decreasing the atomic radiuscloser decreasing the atomic radius

Page 10: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

As you move down a As you move down a group another principal group another principal E-level (shell) is added E-level (shell) is added in each row, making in each row, making atoms larger.atoms larger.

n=1

n=2

n=3

n=5

n=4

Page 11: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Ionic RadiusIonic Radius

DogDogionion, Cat, Cationion, Un, Unionion, On, Onionion, An, Anionion, L, Lionion

Cation – Pos. Charged IonCation – Pos. Charged Ion

Anion – Neg. Charged IonAnion – Neg. Charged Ion

How does the formation of an ion affect the How does the formation of an ion affect the radius, now call the IONIC RADIUS?radius, now call the IONIC RADIUS?

Page 12: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Radii of ions compared to atomsRadii of ions compared to atoms

Cations: (+)Cations: (+)become smaller:become smaller:

1. Reduced the 1. Reduced the number of energy number of energy levels.levels.2. Positive charged 2. Positive charged nucleus attracting nucleus attracting fewer e-.fewer e-.

EX: EX:

Anions: (-)Anions: (-)become larger:become larger:1.1. The number of The number of

electrons is greater electrons is greater than the nuclear than the nuclear charge (echarge (e-- held more held more loosely).loosely).

2.2. Electrons repel.Electrons repel.

Na Na+Cl

Cl-

Metals Nonmetals

Page 13: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

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Page 14: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Trends in Ionic RadiusTrends in Ionic Radius

Page 15: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Oxidation NumberOxidation Number

Pos. or neg. charges on ions that tell how Pos. or neg. charges on ions that tell how many electrons have been gained or lostmany electrons have been gained or lost

Our knowledge of eOur knowledge of e-- configurations and configurations and the stability of noble gases allows us to the stability of noble gases allows us to predict oxidation numbers for elements.predict oxidation numbers for elements.

Page 16: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Oxidation Numbers by GroupOxidation Numbers by Group

1+

2+

Tend to have more than one oxidation number (+1 to +7)

3+ varies 3- 2- 1-

0

3+

3+ or 4+

Page 17: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Ionization EnergyIonization Energy

Energy required to remove an electron Energy required to remove an electron from an atom (form a cation)from an atom (form a cation)

Measured in kJ/molMeasured in kJ/mol

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1 e-

7 e-

Which RED electron would be easier to remove?

Na Cl

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As you move across a period the I.E. ____?As you move across a period the I.E. ____? INCREASESINCREASESAs you move down a family the I.E. ______?As you move down a family the I.E. ______?DECREASESDECREASES

Your turn…Explain why this happens. Use Your turn…Explain why this happens. Use your knowdlege of atomic radius.your knowdlege of atomic radius.

Page 19: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Ionization energy increases diagonally from Ionization energy increases diagonally from bottom left corner to top right corner.bottom left corner to top right corner.

Which element has the highest I.E.?

Page 20: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.
Page 21: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Multiple Ionization EnergiesMultiple Ionization EnergiesAdditional eAdditional e-- can be lost from an atom and can be lost from an atom and

the ionization energies can be measured.the ionization energies can be measured.

IONIZATION ENERGIES (kilojoules per mole)

Element 1st 2nd 3rd 4th 5th

H 1312.0

He 2372.3 5220

Li 520.2 7300 11750

Be 899.5 1760 14850 20900

B 800.6 2420 3660 25020 32660

Page 22: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

ElectronegativityElectronegativity

Ability of an atom to attract an electronAbility of an atom to attract an electronFollows the same general trend as I.E.Follows the same general trend as I.E.Remember that all atoms WANT to be Remember that all atoms WANT to be

STABLE!!STABLE!! (obtain an complete outer shell)(obtain an complete outer shell)The closer they are to completing that The closer they are to completing that

shell the higher the ENshell the higher the EN

Page 23: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Electronegativity ValuesElectronegativity Values

Which element has the highest EN?

Page 24: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Electron AffinityElectron Affinity

The energy change that occurs when an The energy change that occurs when an atom gains an extra electronatom gains an extra electron

Expressed in kJ/molExpressed in kJ/molMostly neg. values, some pos. valuesMostly neg. values, some pos. valuesWhat do the neg. and pos. values mean??What do the neg. and pos. values mean??

Page 25: Periodic Trends Atomic Radius Atomic Radius Ionic Radius Ionic Radius Oxidation Number Oxidation Number Electronegativity Electronegativity Ionization.

Neg. = energy is released during rxn.Neg. = energy is released during rxn.FF(g)(g) + e + e-- F F--

(g) (g) + Energy+ Energy

Pos. = energy is needed to power rxn.Pos. = energy is needed to power rxn.MgMg(g)(g) + e + e-- + Energy Mg + Energy Mg--

(g)(g)

Mg wants to be a cation is energy is Mg wants to be a cation is energy is required to make it an anionrequired to make it an anion