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PERIODIC TABLEChapter 6
How does Electron Configuration relate to the Periodic Table?75020.swf
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DO NOW
Which statement is true? (use Periodic Table)
A. Elements in the same column ↕ has same # of outer shell electrons
B. Elements in the same row ↔ has same # of outer shell electrons
DMITRI MENDELEEV (1869)
produced the first periodic table for the known 63 elements
Arrangement: Increasing atomic mass kept similar elements in a column left blanks for unknown elements
Interesting observations: Mendeleev predicted the properties of the
missing elements.
MENDELEEV’S PT
HENRY MOSELEY (1914)
Arrangement:Increasing atomic number
Interesting observations: Discrepancies in Mendeleev’s table disappeared (Te
before I)
PARTS OF PERIODIC TABLE
Vertical
RowColumnGroupFamily
Period
Same # of occupied energy levels
Groups or familiesSame # of electrons in their outer orbitalShare similar chemical properties
Metal: • Conducts heat & electricity• Ductile• Malleable• Luster
•Solid at room temp. (except Hg)•Forms cations (+)
75133.swfProperties of Metals, Non-metals, & Metalloids
Non-Metal: • Brittle
• S/l/g at room temp.• Forms anions (-)
Metalloids • Semi-conductors• Properties of nonmetals and metals
Note: Most elements are _________
75021.swfMetals, non-metals, & metalloids
metals
TOUR OF THE PERIODIC TABLE
Main-group elements Also called representative elements (s- and p-blocks) E- config: regular & consistent Group: same # of val. e-
TOUR OF THE PERIODIC TABLE
Inner Transition Metals
Hydrogen Most common element in universe
charge: 1+ or 1-
Alkali Metal (Group 1, except H) Highly reactive with water Soft and can be easily cut
Charge:1+
Alkaline-earth metal (Group 2) Less reactive than alkali metals Harder than alkali metals
Charge: 2+
Transition metals (d-block) No identical valence electrons (charge varies) Less reactive than group 1 & 2
Inner Transition metals (f-block)
Nuclei are unstable – radioactive (charge varies)
Halogens (Group 17) Most reactive group of non-metals Likes to react with alkalis to produce salts
charge :1-
Noble gases (Group 18) Low chemical reactivity b/c very stable Outermost energy level is full Does not form ions
Glow brightly when an electric discharge is passed through them
DO NOW: COPY NAMES INTO PG-2
Inner Transition Metals
Octet rule: atoms are most stable when they have 8 val. e-
CATION: (+) ionsAlkali Metals: Na loses 1 e-
1s22s22p63s1 1s22s22p6
(Na) (Na+)
FORMATION OF IONS 75123.swf
Bohr Diagram
E- configNe
ANION: (-) ionsHalogens: Cl gains 1 e-
1s22s22p63s23p5 1s22s22p63s23p6
(Cl) (Cl-)
Ar
PG-7
As you look down a column, the outermost principle energy level __________________. (but the number of valence e-‘s stays the same)
As more and more levels become filled with electrons, the nucleus becomes ______________ effective at attracting the outer electron(s). This is known as the “shielding effect.”
(As you look down a column, even though the nucleus
theoretically is stronger since it has more protons, it is NOT effective at holding onto the outer electrons.)
Which energy level has NO shielding? ____________Which atom holds onto the outer electron tighter, K or Rb?Why? ____ has one more filled level than ____ and therefore
is _____ effective at holding onto the outermost (valence) electron.
INCREASES
LESS
1
LESS
Rb K
Is the shielding effect an issue with a row?_____Row, Period , Series
Val. n=2 n=2 n=2 n=2 n=2 n=2 n=2 n=2
energy level filled ____ ____ ____ ___ ___ ____ ___ ____Levels
The energy level is not changing. What is changing?
Is the nucleus getting stronger?_________. Is it effective?________
In a row, ___________ ___________(and not shielding) determines the trend.
1 1 1 1 1 1 1 2 b/c noble gas
# of electron & protons
YES
YES
NUCLEAR CHARGE
NO
PG-8
Recap:Column: the __________ _________
dictates the trends. Row: the increasing strength of the
__________ dictates the trends.
ELECTRON SHIELDING
NUCLEUS
ATOMIC RADIUS (PG-9)
Distance from nucleus to outer electronsBond radius = ½ distance between nuclei of adjacent atoms.
75092.swf
ATOMIC RADIUS
Down a Group: IncreasesReason: more energy levels more shielding
Across a Period: DecreasesReason: More nuclear charge (+) pulls outer most
e- closer to nucleus
IONIC RADII (PG-9)
Metals tend to _________ electrons and become ____________ions. (gain or lose) positive or negative) ** (metal ions are ___________than metal atoms)
(smaller or larger)
Non- metals tend to _______ electrons and become __________ ions. (gain or lose) (positive or negative)
** (non-metal ions are ______________than non-metal atoms) (smaller or larger)
lose positive
smaller
gain negative
larger
IONIZATION ENERGY (IE) – PG10
Energy required to remove an electron from an atom or ion (form (+) ion).
e+
neutral atom
A + ionizati
on energy
ion el
A +
ec
tron
IONIZATION ENERGY (IE)
Down a Group: Decreases (easier to remove an electron)
Reason:1. more energy levels (outermost electrons are farther from
nucleus)
2. more shielding (less attraction btw p+ & val. e-)
Across a Period: Increases (harder to remove an electron)
Reason:1. more nuclear charge, p+ ↑2. radius decreases Electron-shielding remains the same
Lower down in a column the atoms are larger / smaller and have more attractiveness / shielding so it is easier to remove an e- from the outer shell.
It is harder/easier to remove an electron from a small atom with
no shielding.
It gets harder/easier to remove that electron as you move to the right as it approaches a perfect octet.
Which column would be very difficult to go in and remove and
electron from? Noble gases
So the column with the highest Ionization Energy = Group # 18, Noble gases
Ionization Energy pg-10Circle the correction answer & answer the last 2 questions
Which element has the least IE? the most?
IE
#3 ELECTRONEGATIVITY (PG-11)
the attraction of an atom to a pair of electrons in a bond
Fluorine has the highest value of “4.0”
**EXCEPT NOBLE GASES
ELECTRONEGATIVITY (EN)
Down a Group: Decreases (less attraction towards bonding e-)
Reason:1. more energy levels2. more shielding
Across a Period: Increases (more attraction towards bonding e-)
Reason:1. radius decreases (val. e- closer to nucleus)
2. nuclear charge increases, p+ ↑
Fluorine atom pulls harder on the shared pair of electrons. They are shared “unevenly”
Electronegativity of Fluorine is > , = , < the electronegativity of hydrogen
Chlorine atoms share the pair of electrons “evenly”
Electronegativity of Chlorine is > , = , < the electronegativity of Chlorine
In water, does Hydrogen or Oxygen pull harder on the shared pair of electrons? ____________
Which column does NOT bond with any element (because it has a perfect
octet)? ____________________ (No electronegativity values are assigned)NOBLE GASES
MOLECULE/MOLE/MASS CONVERSIONS FOR DIATOMIC ELEMENTS
Atomic mass:mass in grams = 1 mole of that elementExample: 12 g C = 1 mol C
Molecular mass:mass of a molecule = 1 mole of that moleculeExample: 32 g O2 = 1 mol O2
Diatomic Elements (BrINClHOF): Br2 I2 N2 Cl2 H2
O2 F2
Elements found in pairs
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