1 mr. shieldsregents chemistry u08 l06 2 as we’ve seen, of the 111 named elements 87 are metals....
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11Mr. Shields Regents Chemistry U08 L06
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As we’ve seen, of the 111 named elements 87 are metals. This is about 78% of the periodic table!
METALS
What defines metallic character? Are some metals moreMetallic than others? What determines metallic reactivity?
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MetalsMetalsOne of the characteristics of metals is that they have A tendency to want to lose electrons (i.e they have low IE)
- Will form positive ions- Metals have positive oxidation numbers
As we go down a group what happens to IE?
IE Decreases
And as we go across a period what is the trend for IE?
IE Increases
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Decreasin
g IE
Increasing I.E.
Ionization Energy Trends
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MetalsMetalsWe know that the ease with which a metal loses it’s valence electrons increases with increasing atomic radii
Relative Atomic radiiLithium IE = 520
Rubidium IE = 403
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Metallic CharacterMetallic Character
Since losing electrons is a characteristic of metals
How easily a element can lose it’s electron definesMETALLIC CHARACTER
- i.e The lower the IE the greater the metallic character
METALLIC CHARACTER INCREASES GOING DOWNA GROUP AND…
METALLIC CHARACTER DECREASES LEFT TO RIGHTACROSS A ROW (PERIOD)
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Metallic CharacterMetallic Character
Li Be B C N O F
Na Mg Al Si P S Cl
K Ca… Ga Ge As
Rb Sr
Cs Ba
Fr Ra
Decreasing Metallic CharacterIn
creasi
ng M
eta
llic
Chara
cter
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Metallic CharacterMetallic CharacterSo if metallic character increases down a group andDecreases across a period what is the most metallicelement and what is the least metallic of all elements?
Most metallic: Francium
Least Metallic of all elements: Fluorine
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Reaction of K (top) and Ca with water
Group 1
Group 2How can you tell which metalis more reactive?
How could you predict one tobe more reactive than theother?
Metal (2K) + 2H20 H2 + 2KOH
H2 Gas
Reaction Equation forAlkali metals with water:
Metal hydroxide
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Group 1 Metallic ReactivityGroup 1 Metallic Reactivity
Lithium is the least reactive Alkali metal
Na and K react violently with water; K even more so Than Na. It’s reaction is so exothermic it will ignite theLiberated Hydrogen
Rubidium will burst into even if exposed to air
The most reactive Alkali metals areCesium & Francium (the most reactive)
Li
NaK
Rb
CsFr
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Potassium will react violently with water
http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA0/MOVIES/NACL1.html
Movie: Reaction of Na and Cl2 (requires Quicktime)
These metals will react with many different elements and Compounds. Sodium, less reactive than potassium,still reacts violently with Chlorine.