Transcript 400 Chem periodic table

The Periodic Table
• Antoine LaVoisier - the “father of chemistry”
– By late 1700’s had compiled list of 23 elements
• Chemical-based industry in 1800s greatly
expanded the use and discovery of elements
• In 1864, John Newlands: “Law of Octaves”
– Chemical and physical properties repeat every 8
elements
• Dmitri Mendeleev – Russian scientist
– In 1872, presented the first periodic table of elements
– The “father of the periodic table”
Mendeleev’s Periodic Table
Periodic Table
Moseley: Noticed that the periodic table worked better if
ordered by Atomic Number (Protons) rather
than Atomic Mass
Periodic
Law:
A predictable repetition of chemical and
physical properties of the elements is found
when arranged by atomic number.
The Per iodic Tabl e of El ement s
1
1
18
IA
VIIIA
a
H
Hydrogen
1.01
3
2.2
Li
b
c
IIA
4
Lithium
H
2
2
a = atomic number
d
He
b = element name
c = atomic mass
13
14
15
16
17
d = electronegativity
IIIA
IVA
VA
VIA
VIIA
5
Be
Beryllium
6.94
1.0 9.01
11
12
22.99
1.6
10.81
19
3
4
5
6
7
1.3
IIIB
IVB
VB
VIB
VIIB
20
21
22
23
24
8
9
10
11
12
IB
IIB
[-----------------------VIIIB-----------------------]
25
26
27
28
29
C
2.0 12.01
8
N
Nitrogen
2.6 14.01
14
O
Oxygen
3.0 16.00
15
9
F
16
Ne
Fluorine
3.4 19.00
17
Si
P
S
Cl
Phosphorus
Sulfur
Chlorine
31
32
2.2 32.07
33
2.6 35.45
34
0.0
18
Silicon
1.9 30.97
Neon
4.0 20.18
Al
1.6 28.09
0.0
10
Aluminum
26.98
30
7
Carbon
13
Magnesium
0.9 24.31
B
Boron
Na Mg
Sodium
6
Helium
4.00
Ar
Argon
3.2 39.95
35
0.0
36
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Potassium
Calcium
Scandium
Titanium
Vanadium
Chromium
Manganese
Iron
Cobalt
Nickel
Copper
Zinc
Gallium
Germanium
Arsenic
Selenium
Bromine
Krypton
39.10
0.8 40.08
37
1.0 44.96
38
1.4 47.88
39
1.5 50.94
40
1.6 52.00
41
Rb
Sr
Y
Zr
Nb
Rubidium
Strontium
Yttrium
Zirconium
Niobium
85.47
0.8 87.62
55
1.0 88.91
1.2 91.22
56
1.3 92.91
72
1.7 54.94
42
Mo
Tc
2.2 98.00
74
1.8 58.93
44
Molybdenum Technetium
1.6 95.94
73
1.6 55.85
43
1.9 63.55
46
Cd
In
Sn
Sb
Te
I
Cadmium
Indium
Tin
Antimony
Tellurium
Iodine
76
2.3 106.42
77
2.2 107.87
78
79
Ta
W
Re
Os
Ir
Pt
Tantalum
Tungsten
Rhenium
Osmium
Iridium
Platinum
87
104
88
Fr
Ra
Francium
Radium
223.00
0.7 226.03
105
Rf
106
Ha
Rutherfordium Hahnium
261.0
262.0
-
0.9
57
58
59
La
Ce
Lanthanum
Cerium
138.91
1.1 140.12
89
2.4 186.21
107
2.2 192.22
108
Sg
Hs
Bh
Hassium
Bohrium
263.0
-
262.0
-
265.0
61
Nd
-
62
Pm Sm
80
Gold
81
Mercury
2.3 196.97
2.5 200.59
111
Ds
-
281.0
-
64
Eu
280.0
-
65
Gd
83
2.1 126.90
84
Xenon
2.7 131.29
85
Tl
Pb
Bi
Po
At
Lead
Bismuth
Polonium
Astatine
2.0 207.20
2.3 208.98
114
115
2.0 209.00
2.0 210.00
116
91
92
93
94
95
Ac
Th
Pa
U
Np
Pu
Thorium
Protactinium
Uranium
Neptunium
Plutonium
1.3 231.04
1.5 238.03
1.4 237.05
1.4 244.0
96
97
285.0
-
Rn
1.3 243.0
Curium
1.3 247.0
Dy
68
Ho
69
70
Er Tm Yb
100
99
Cf
1.3 251.0
101
102
Es Fm Md No
Berkelium Californium Einsteinium
1.3 247.0
Radon
2.2 222.00
117
0.0
118
Ununtrium Ununquadium Ununpentium Ununhexium Ununseptium Ununoctium
284.0
289.0
288.0
293.0
294.0
294.0
-
67
98
Am Cm Bk
Americium
0.0
86
Cn Uut Uuq Uup Uuh Uus Uuo
66
Tb
2.1 127.60
Thallium
113
Meitnerium Darmstadtium Roentgenium Copernicium
266.0
2.0 121.76
82
2.0 204.38
112
Rg
1.8 118.71
Xe
71
Lu
Praseodymium Neodymium Promethium Samarium
Europium Gadolinium Terbium Dysprosium Holmium
Erbium
Thulium
Ytterbium
Lutetium
1.1 140.91
1.1 144.24
1.1 145.00
1.1 150.36
1.2 151.97
1.2 157.25
1.2 158.93 1.2 162.50 1.2 164.93 1.2 167.26 1.2 168.93 1.3 173.04 1.1 174.97 1.3
90
1.1 232.04
Mt
1.7 114.82
Au Hg
110
63
Actinium
227.00
2.2 195.08
109
Seaborgium
60
Pr
1.9 190.20
1.9 112.41
0.0
54
Silver
2.2 102.91
3.0 83.80
53
Ag
Hf
1.5 183.85
2.6 79.90
52
Pd
Hafnium
1.3 180.95
2.2 78.96
51
Palladium
Barium
178.49
2.0 74.92
50
Rh
Ba
0.9
1.8 72.61
49
Rhodium
Cs
0.8 137.33
1.7 69.72
48
Ru
Cesium
132.91
1.9 65.38
47
Ruthenium
1.9 101.07
75
1.9 58.69
45
1.3 252.0
Fermium
1.3 257.0
103
Lr
Mendelevium Nobelium Lawrencium
1.3 258.0
1.3 259.0
1.3 260.0
-
Periodic Table Blocks
Periodic
Brainteasers/Puns
•
•
•
•
•
•
•
•
What you do in a play?
What you do to a wrinkled shirt?
Policeman.
Superman’s weakness.
Your brother or mine
Name of a goofy convict
Not an exciting person
What a doctor does to his patients (3x).
Trends in Alkali Metals
Element
Melting Point (C)
Boiling Point
Radius (pm)
Lithium
181
1347
152
Sodium
98
897
186
Potassium
63
766
227
Rubidium
39
688
248
Cesium
28
675
248
Francium
???
???
???
Francium is one of the rarest elements on Earth. It
is the radioactive byproduct of the decay of
Uranium and Actinium. It only has a half-life of 22
minutes, so it is very hard to analyze. How can we
predict its physical properties?
1600
1400
1200
1000
Boiling Point
800
600
400
Radius
200
Melting Point
0
3
11
19
37
Atomic number of Alkali Metal
55
Atomic Radius
=1/2 distance between 2 nuclei
Atomic Radius Trends
Periodic Table Trends
Element’s Atomic Radius determined by
1. Attraction of electrons by protons.
2. Repulsion between electrons.
3. Number of Principal Energy Shells.
Net Effective Nuclear Charge:
• Is the net positive charge experienced by electron in multielectron atom.
• Protons always added to nucleus, but electron positions
can change as atomic number increases (energy levels).
• Three factors control the net charge: size of energy levels,
nuclear charge and the shielding effect.
• These determine trends in atomic properties
Shielding vs. Nuclear Charge
Effects on Periodic Table Trends
• Shielding effect - inner electrons partially block outer
electrons from the pull of the positively charged nucleus
– The more principal energy levels, the more layers of inner
electrons available to shield the valence electrons
– Mainly affects properties of atoms going down a Group
– s orbital e- can modestly shield p orbital e- on same level
• Nuclear charge - attraction for all electrons by the
positively charged nucleus
– The higher the atomic number, the more protons in the nucleus,
and the stronger the pull of the nucleus (greater nuclear charge)
– Affects properties of atoms going left to right across a Period since
those electrons are all on the same level and have a similar
shielding effect.
Atomic Radius Trends
•
Across Periods: radius decreases as the
increasing positive nuclear charge
overwhelms the repulsive force of
additional electrons.
•
Down Groups: radius increases as size of
shells and shielding increase
Ions
• An ion is an atom or bonded group of atoms with a
positive or negative charge.
• Atoms become ions when they either lose or gain
electrons.
Cats are
Positive!
Ions
• The size changes due to either greater repulsion of
more electrons (anions), or increased protron
attraction of fewer remaining electrons (cations).
Types of Ions and Effect on Radius
• Cations = Positive Ions (atoms that have lost
electron). Radius decreases. Ex: Ca+2
• Anions = Negative Ions (atoms that have
gained electrons). Radius increases. Ex: O-2
Metals usually form
cations.
Non-metals usually
form anions
• Ionization energy is the energy required to
remove an electron from an atom (form ion).
Ionization Energy:
Increases across a Period
As you go across a period, one electron and one
proton is added to the atom
But since the electron is added to the same
energy level, the higher nuclear charge (from the
additional protons in the nucleus) attracts the all
of outer electrons more strongly.
Thus the energy required to remove an electron
becomes larger across the period (left to right).
Li
Be
B
C
N
O
F
Ionization Energy:
Decreases down a group
Lithium
Sodium
As you move down a group, the size of
the atom increases as it adds more
energy levels. This increases the
distance between the positive nucleus
and electron.
This also causes a greater shielding
effect, thus the electron is easier it is to
remove.
Potassium
Rubidium
The easier it is to remove an electron, the
more reactive an element tends to be.
Ionization Energy Trends
Electron Affinity
X + e− → X −
• Electron Affinity is effectively the opposite of
ionization energy.
• It is the energy released by an atom when it
gains an electron (exothermic).
• The halogens have the greatest electron
affinity because gaining one electron gets
them to noble gas configuration.
• Electron Affinity generally increases left to
right, but is erratic in behavior down groups..
Electron Affinities (kJ/mol)
The first electron
affinities of the
group 17 elements
F
-328 kJ/mol
Cl
-349 kJ/mol
Br
-324 kJ/mol
I
-295 kJ/mol
• The electronegativity of an element indicates
its relative ability to attract electrons in a
chemical bond. Key to chemical bonding.
• Fluorine is the most electronegative = 4
Overall Electronegativity Trend
•Radius DECREASES
•Ionization energy INCREASES
•Electron Affinity INCREASES
Electronegativity INCREASES
•Radius INCREASES
•Ionization Energy DECREASES
•Electronegativity DECREASES
LEVELS & SHIELDING INCREASE
NUMBER OF PROTONS INCREASES
(Nuclear Charge Increases)
The Octet Rule
What makes atoms form certain ions?
• Octet Rule: Atoms tend to gain, lose or share electrons in
order to acquire a full set of eight valence electrons.
• Useful in determining what kind of ion an element is likely
to form. They will add or lose electrons to get to s2p6.
• Elements on the left side tend to lose electrons, elements
on right tend to gain electrons to reach the noble gas
configuration.
• Na: 1s2 2s2 2p6 3s1 Obtains noble gas configuration (and a
full valence octet) by losing an electron (Na+).
The Octet Rule
• What are likely oxidation states (charges) of ions to
form from the following? (HINT: add/lose fewest
VALENCE electrons to get them to noble gas configuration)
– Calcium: 1s2 2s2 2p6 3s2 3p6 4s2, thus Ca2+ ion
– Potassium:
– Chlorine:
– Oxygen:
– Phosphorus:
– Zinc:
– Iron: 1s2 2s2 2p6 3s2 3p6 4s2 3d6
Spiral Periodic Table