Development of Periodic Table

Development of Periodic Table

Law of Octaves

Original Periodic Table

Arranged the 62 known elements into groups of seven according to increasing atomic mass. He proposed that an eighth element would then repeat the properties of the first element in the previous group.

Observed properties and organized elementsby atomic mass.

J.A.R. Newlands (1864)

D. Mendeleev (1871)

Henry Mosley (1914)Revised Periodic Table

Reorganized table by atomic number, based on observations with atomic spectra

Dmitri Mendeleev (1871)

• Russian• Invented “Periodic Table”• Organized all known elements

by properties and by atomic mass

• Predicted existence of several unknown elements

Dmitri Mendeleev

Elements Properties are PredictedProperty Mendeleev’s Predictions in 1871 Observed Properties

Molar Mass

Oxide formula

Density of oxide

Solubility of oxide

Scandium (Discovered in 1877)44 g

M2O3

3.5 g / ml

Dissolves in acids

43.7 g

Sc2O3

3.86 g / ml

Dissolves in acids

Molar mass

Density of metal

Melting temperature

Oxide formula

Solubility of oxide

Gallium (Discovered in 1875)68 g

6.0 g / ml

Low

M2O3

Dissolves in ammonia solution

69.4 g

5.96 g / ml

30 0C

Ga2O3

Dissolves in ammonia

Molar mass

Density of metal

Color of metal

Melting temperature

Oxide formula

Density of oxide

Chloride formula

Density of chloride

Boiling temperature

of chloride

Germanium (Discovered in 1886)72 g

5.5 g / ml

Dark gray

High

MO2

4.7 g / ml

MCl4

1.9 g / ml

Below 100 oC

71.9 g

5.47 g / ml

Grayish, white

900 0C

GeO2

4.70 g / ml

GeCl4

1.89 g / ml

86 0C

O’Connor Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 119,

Mendeleev’s Periodic Table

Period Period

11

Group IGroup I IIII IIIIII IVIV VV VIVI VIIVII VIIIVIII

H = 1

22 Li = 7 Be= 9.4 B = 11 C = 12 N = 14 O = 16 F = 19 F = 19

33 Na = 23 Mg = 24 Al = 27.3 Si = 28 P = 31 S = 32 C = 35.5

44 K = 39 Ca = 40 ? = 44 Ti = 48 V = 51 Cr = 52 Mn = 55Fe =56, Co = 59,

Ni = 59

55 Cu = 63 Zn = 65 ? = 68 ? = 72 As = 75 Se = 78 Br = 80

66 Rb = 85 Sr = 87 ? Yt = 88 Zr = 90 Nb = 94 Mo = 96 ? = 100 Ru= 104, Rh = 104, Pd = 106

77 Ag = 108 Cd = 112 In = 113 Sn = 118 Sb = 122 Te = 125 J = 127

88 Cs = 133 Ba = 137 ?Di = 138 ?Ce = 140

99

1010 ?Er = 178 ?La = 180 Ta = 182 W = 184Os = 195, Ir = 197,

Pt = 198

1111 Au = 199 Hg = 200 Tl = 204 Pb = 207 Bi = 208

1212 Th = 231 U = 240

Modern Periodic Table

• Henry G.J. Moseley • Determined the atomic

numbers of elements from their X-ray spectra (1914)

• Arranged elements by increasing atomic number

• Killed in WW I at age 28

(Battle of Gallipoli in Turkey)

1887 - 1915

P

Zn As

Sb

Pt Bi

Midd. -1700

Cr Mn

Li

K

N O F

Na

BBe

H

Al Si Cl

Ca Ti V Co Ni Se Br

Sr Y Zr Nb Mo Rh Pd Cd Te I

Ba Ta W Os Ir

Mg

Ce Tb Er

Th U

1735-1843

Discovering the Periodic Table

C

S

Fe Cu

Ag Sn

Au Hg Pb

Ancient Times

He

Sc Ga Ge

Rb Ru In

Cs Tl

Pr Nd Sm Gd Dy Ho Tm Yb

La

1843-1886 Ne

Ar

Kr

Xe

Po Rn

Ra

Eu Lu

Pa

Ac

1894-1918

Tc

Hf Re At

Fr

Pm

Np Pu Am Cm Bk Cf Es Fm Md No Lr

1923-1961

Rf Db Sg Bh Hs Mt

1965-

Journal of Chemical Education, Sept. 1989

Valence Electrons

- Electrons in outer most energy level (“shell”)

- Electrons which are most important in bonding

- Elements with eight valance electrons are the most stable (i.e. inert gases in group 18)

- Valance electrons useful for writing short-hand electron configuration (i.e. Na = [Ne]3s1)

s-block1st Period

1s11st column of s-block

Periodic Patterns

• Example - Hydrogen

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

[Ar] 4s2 3d10 4p2

Periodic Patterns

• Example - GermaniumGermanium


Ge72.61

32

The Octet Rule and Common Ions

Oxygen atomO

1s22s22p4

Fluorine atomF

1s22s22p5

Sodium atomNa

1s22s22p63s1

Magnesium atomMg

1s22s22p63s2

8+-

--

-

- --

-9+-

--

-

--

--

-

11+-

--

-

-

--

--

-

-

12+-

--

-

-

--

--

--

-

11+-

--

-

-

--

--

-

12+-

--

-

-

--

--

-

Oxygen ionO2-

1s22s22p6

Fluorine ionF1-

1s22s22p6

Sodium ionNa1+

1s22s22p6

Magnesium ionMg2+

1s22s22p6

10+-

--

-

-

--

--

-

Neon atomNe

1s22s22p6

+1e+1e-- -1e-1e-- -2e-2e--+2e+2e--

8+-

--

-

- --

-

-

-9+-

--

-

--

--

-

-

Orbitals Being Filled

1s

2s

3s

4s

5s

6s

7s

3d

4d

5d

6d

2p

3p

4p

5p

6p

1s

La

Ac

1

13 14 15 16 17

4f

5f

Lanthanide series

Actinide series

Groups or Families 18

Per

iods

1 2

2

3

4

5

6

7

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 345

Stability

• Full energy level

1

2

3

4

5

6

7

• Full sublevel (s, p, d, f)• Half-full sublevel


Stability

• Ion Formation– Atoms gain or lose electrons to become more

stable.– Isoelectronic with the Noble Gases.


The Periodic Table

Li

3

He

2

C

6

N

7

O

8

F

9

Ne

10

Na

11

B

5

Be

4

H

1

Al

13

Si

14

P

15

S

16

Cl

17

Ar

18

K

19

Ca

20

Sc

21

Ti

22

V

23

Cr

24

Mn

25

Fe

26

Co

27

Ni

28

Cu

29

Zn

30

Ga

31

Ge

32

As

33

Se

34

Br

35

Kr

36

Rb

37

Sr

38

Y

39

Zr

40

Nb

41

Mo

42

Tc

43

Ru

44

Rh

45

Pd

46

Ag

47

Cd

48

In

49

Sn

50

Sb

51

Te

52

I

53

Xe

54

Cs

55

Ba

56

Hf

72

Ta

73

W

74

Re

75

Os

76

Ir

77

Pt

78

Au

79

Hg

80

Tl

81

Pb

82

Bi

83

Po

84

At

85

Rn

86

Fr

87

Ra

88

Rf

104

Db

105

Sg

106

Bh

107

Hs

108

Mt

109

Mg

12

Ce

58

Pr

59

Nd

60

Pm

61

Sm

62

Eu

63

Gd

64

Tb

65

Dy

66

Ho

67

Er

68

Tm

69

Yb

70

Lu

71

Th

90

Pa

91

U

92

Np

93

Pu

94

Am

95

Cm

96

Bk

97

Cf

98

Es

99

Fm

100

Md

101

No

102

Lr

103

La

57

Ac

89

1

2

3 4 5 6 7

Lanthanides

Actinides

Noblegases

Halogens

Transition metals

Alkalineearth metals

Alk

ali

me

tals

8 9 10 11 12

13 14 15 16 17

18

Uun

110

Uuu

111

Uub

112

Uuq

113

Uuh

116

Uuo

118

Metals, Nonmetals, & Metalloids1

2

3

4

5

6

7

Metals

Metalloids

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 349

Nonmetals

Metallic Propertiesmetallic character increases

nonmetallic character increases

met

allic

cha

ract

er in

crea

ses

non

met

allic

cha

ract

er in

crea

ses

Properties of Metals, Nonmetals, and Metalloids

METALSMETALS

NONMETALSNONMETALS

METALLOIDSMETALLOIDS

malleable, lustrous, ductile, good conductors of heat and electricity, high densities and melting points, can form alloys (2 or more metals), react with acids

gases or brittle solids at room temperature, poor conductors of heat and electricity (insulators), low densities, low melting points

(Semi-metals)dull, brittle, semi-conductors (used in computer chips), mostly solids at room temperature, properties of both metals and nonmetals

Reactivity

GROUP 1 (ALKALI METALS) and 2 (ALKALINE-EARTH)GROUP 1 (ALKALI METALS) and 2 (ALKALINE-EARTH)

GROUP 17 HALOGENSGROUP 17 HALOGENS

GROUP 18 NOBLE GASES

Both groups very reactive; most stable by losing 1-2 electrons. Group 1 often stored in oil (most reactive group)

Most reactive of non-metals; most stable by gaining one electron

Low chemical reactivity; very stable; octet valence electrons

1

2

3

4

5

6

Li

0.53

He

0.126

C

2.26

N

0.81

O

1.14

F

1.11

Ne

1.204

Na

0.97

B

2.5

Be

1.8

H

0.071

Al

2.70

Si

2.4

P

1.82w

S

2.07

Cl

1.557

Ar

1.402

K

0.86

Ca

1.55

Sc

(2.5)

Ti

4.5

V

5.96

Cr

7.1

Mn

7.4

Fe

7.86

Co

8.9

Ni

8.90

Cu

8.92

Zn

7.14

Ga

5.91

Ge

5.36

As

5,7

Se

4.7

Br

3.119

Kr

2.6

Rb

1.53

Sr

2.6

Y

5.51

Zr

6.4

Nb

8.4

Mo

10.2

Tc

11.5

Ru

12.5

Rh

12.5

Pd

12.0

Ag

10.5

Cd

8.6

In

7.3

Sn

7.3

Sb

6.7

Te

6.1

I

4.93

Xe

3.06

Cs

1.90

Ba

3.5

Hf

13.1

Ta

16.6

W

19.3

Re

21.4

Os

22.48

Ir

22.4

Pt

21.45

Au

19.3

Hg

13.55

Tl

11.85

Pb

11.34

Bi

9.8

Po

9.4

At

---

Rn

4.4

Mg

1.74

1

2

3

4

5

6

Densities of Elements

Mg

1.74

SymbolDensity in g/cm3C, for gases, in g/L

8.0 – 11.9 g/cm3 12.0 – 17.9 g/cm3 > 18.0 g/cm3

La

6.7

Atomic Radius

Li

Na

K

Rb

Cs

ClSPSiAl

BrSeAsGeGa

ITeSbSnIn

Tl Pb Bi

Mg

Ca

Sr

Ba

Be FONCB

1.52 1.11

1.86 1.60

2.31 1.97

2.44 2.15

2.62 2.17

0.88 0.77 0.70 0.66 0.64

1.43 1.17 1.10 1.04 0.99

1.22 1.22 1.21 1.17 1.14

1.62 1.40 1.41 1.37 1.33

1.71 1.75 1.46

1 2 13 14 15 16 17

= 1 Angstrom

1

2

3

4 5

6

7

Atomic radius increases with energy levels, since orbital size and shielding increase. Radius decreases with increased nuclear charge.

Radius Decreases RIGHT and Increases DOWN

Atomic Radii

Li

Na

K

Rb

Cs

ClSPSiAl

BrSeAsGeGa

ITeSbSnIn

Tl Pb Bi

Mg

Ca

Sr

Ba

Be FONCB

1.52 1.11

1.86 1.60

2.31 1.97

2.44 2.15

2.62 2.17

0.88 0.77 0.70 0.66 0.64

1.43 1.17 1.10 1.04 0.99

1.22 1.22 1.21 1.17 1.14

1.62 1.40 1.41 1.37 1.33

1.71 1.75 1.46

IA IIA IIIA IVA VA VIA VIIA

= 1 Angstrom

0.60 0.31

0.95 0.65

1.33 0.99

1.48 1.13

1.69 1.35

1.71 1.40 1.36

0.50 1.84 1.81

0.62 1.98 1.85

0.81 2.21 2.16

0.95

1 2 13 15 16 17

= 1 Angstrom

Li1+ Be2+

Na1+ Mg2+

Ba2+

Sr2+

Ca2+K1+

Rb1+

Cs1+

Cl1-

N3- O2- F1-

S2-

Se2- Br1-

Te2- I1-

Al3+

Ga3+

In3+

Tl3+

Ionic Radii

Trends in Atomic and Ionic Size

152

186

227

Li

Na

K

60

Li+

95

Na+

133

K+

e

e

e

F-

136

Cl-

181

Br-

195

F

Cl

Br

64

99

114

e

e

e

Metals NonmetalsGroup 1

Al

143

50

ee

e

Group 13 Group 17

Cations are smaller than parent atoms Anions are larger than parent atoms

Al3+

Firs

t Ion

izat

ion

ener

gy

Atomic number

• Ne has a lower IE than He• Both are full energy

levels,• Ne has more shielding• Greater distance

H

He

Li

Be

B

C

N

O

F

Nen

2s2p

1s

Firs

t Ion

izat

ion

ener

gy

Atomic number

Na has a lower IE than Li Both are s1

Na has more shielding Greater distance

H

He

Li

Be

B

C

N

O

F

Ne

Na

n

2s2p

1s

3s

0

50

100

150

200

250

0 5 10 15 20Atomic Number

Ato

mic

Ra

diu

s (

pm

)Atomic Radius

Li

ArNe

KNa

1

2

3

4

5

6

Li

180.5

He

-269.7

C

4100

N

-210.1

O

-218.8

F

-219.6

Ne

-248.6

Na

98

B

2027

Be

1283

H

-259.2

Al

660

Si

1423

P

44.2

S

119

Cl

-101

Ar

-189.6

K

63.2

Ca

850

Sc

1423

Ti

1677

V

1917

Cr

1900

Mn

1244

Fe

1539

Co

1495

Ni

1455

Cu

1083

Zn

420

Ga

29.78

Ge

960

As

817

Se

217.4

Br

-7.2

Kr

-157.2

Rb

38.8

Sr

770

Y

1500

Zr

1852

Nb

2487

Mo

2610

Tc

2127

Ru

2427

Rh

1966

Pd

1550

Ag

961

Cd

321

In

156.2

Sn

231.9

Sb

630.5

Te

450

I

113.6

Xe

-111.9

Cs

28.6

Ba

710

Hf

2222

Ta

2997

W

3380

Re

3180

Os

2727

Ir

2454

Pt

1769

Au

1063

Hg

-38.9

Tl

303.6

Pb

327.4

Bi

271.3

Po

254

At Rn

-71

Mg

650

Mg

650

1

2

3

4

5

6

Melting PointsSymbolMelting point oC

> 3000 oC 2000 - 3000 oC

La

920

Ralph A. Burns, Fundamentals of Chemistry , 1999, page 1999

1

2

3

4 5

6

7

Generally highest in the middle of d and p orbitals

Melting/Boiling Points

Nuclear Fusion

Sun

+ +

Fourhydrogen

nuclei(protons)

Two betaparticles

(electrons)

Oneheliumnucleus

He e2 H4 4

2

0

1-

1

1 + Energy (gamma ray)

Conservation of Mass…mass is converted into energy

Hydrogen (H2) H = 1.008 amuHelium (He) He = 4.004 amu

FUSIONFUSION

2 H2 1 He + ENERGY

1.008 amux 44.0032 amu = 4.004 amu + 0.028 amu

This relationship was discovered by Albert EinsteinE = mcE = mc22

Energy= (mass) (speed of light)2

Nuclear Fusion

Sun

+ +

Helium Helium Beryllium

Be He He 84

42

42 + Energy (gamma ray)

Synthetic Elements

• Transuranium Elements– elements with atomic #s above 92– synthetically produced in nuclear reactors and accelerators– most decay very rapidly

Pu He U 24294

42

23892


Documents

Development of Periodic Table