Atomic Structure :  Development of Elements and the Periodic Table

1661 - Robert Boyle

  • Defined an element as a substance that could not be broken down

  • into a simpler substance by a chemical reaction. 
 
Li
Na
K
Ca
Sr
Ba
S
Se
Te
Cl
Br
I
Mn
Cr
Fe
H 1
Li 2
Be 3
B 4
C 5
N 6
O 7
F 8
Na 9
Mg 10
Al 11
Si 12
P 13
S 14
Cl 15
K 16
Ca 17
Cr 19
Ti 18
Mn 20
Fe 21
Co & Ni 22
Cu 23
Zn 24
Y 25
In 26
As 27
Se 28
Br 29
Rb 30
Sr 31
Ce & La 33
Zr 32
Bi & Mo 34
Rh & Ru 35
Pd 36
Ag 37
Cd 38
U 40
Sn 39
Sb 41
Te 43
I 42
Cs 44
Ba & V 45
Ta 46
W 47
Nb 48
Au 49
Pt & Ir 50
Os 51
Hg 52
Tl 53
Pb 54
Bi 55
Th 56

1869 - Dmitri Ivanovitch Mendeléev - Created the first accepted version of the periodic table.

  • Grouped elements on the basis of similar chemical properties. 
  • Left blank spaces open to add new elements where he predicted they would occur. 
  • Accepted minor inversions when placing the elements in order of increasing atomic mass. 
  • Predicted properties for undiscovered elements, allowing for his theories to be tested. 

[Image]

                A version of Mendeléev's periodic table published in the journal Annalen der Chemie in 1871.

The Modern Periodic Table

1944 - Glenn T. Seaborg - Created the modern version of the periodic table.

  • Actinide Hypothesis and Periodic Table Reconstruction

  •             "In 1944, I formulated the “actinide concept” of heavy element electronic structure. This concept predicted that the fourteen actinides, including the first eleven transuranium elements, would form a transition series analogous to the rare-earth series of lanthanide elements and therefore show how the transuranium elements fit into the  periodic table." 
                "I was warned at the time that it was professional suicide to promote this idea, which has since been called one of the most significant changes in the periodic table since Mendeleev’s 19th century design. Luckily, I stuck  to my guns and have seen the actinide concept become the foundation for many significant discoveries in heavy element research."

    Glenn Seaborg was the only individual to have an element of the periodic table named after him while still living.  He autographed the periodic table in Room 100 during a visit to TAMU in 1998.


solid liquid T H E   P E R I O D I C   T A B L E gas synth
Discoverer
1
H
AtomicWeight  Melt|Boil(C) 2
He
3
Li
4
Be
Shell  Isotopes 5
B
6
C
7
N
8
O
9
F
10
Ne
11
Na
12
Mg
Orbital  SpecificGravity 13
Al
14
Si
15
P
16
S
17
Cl
18
Ar

19
K

20
Ca

21
Sc

22
Ti

23
V

24
Cr

25
Mn

26
Fe

27
Co

28
Ni

29
Cu

30
Zn

31
Ga

32
Ge

33
As

34
Se
r >36
Kr
37
Rb
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
55
Cs
56
Ba
57
La
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
87
Fr
88
Ra
89
Ac
104
Rh
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Uun
111
Uuu
112
Uub
113
Uut
114
Uuq
lanthanons 58
Ce
59
Pr
60
Nd
61
Pm
62
Sm
53
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb
71
Lu
 
actinons   90
Th
91
Pa
92
U
93
Np
94
Pu
95
Am
96
Cm
97
Bk
98
Cf
99
Es
100
Fm
101
Md
102
No
103
Lr
 

See links to periodic table sites below!

Period - A horizontal row in the periodic table.

The energy levels of the s and p orbitals are numbered by the row in which they are located.

e.g.  The 2s orbital is in the second row (Li and Be) and the 3p orbitals are in the third row (Al, Si, P, S, Cl, Ar)

The d orbitals are placed one row below their energy level.

e.g.  The 3d orbitals are in the fourth row

Group - A vertical column, or family, in the periodic table.

Numbered in two ways:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
IA
IIA
IIIB
IVB
VB
VIB
VIIB
VIIIB
IB
IIB
IIIA
IVA
VA
VIA
VIIA
VIIIA
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Ac
Unq
Unp
Unh
Uns
Uno
Une