Periodic Table & Periodic Law

Organizing the Elements A few elements, such as gold and copper, have

been known for thousands of years - since

ancient times

Yet, only about 13 had been identified by the

year 1700.

As more were discovered, chemists realized

they needed a way to organize the elements.

1790’s Antoine Lavoisier compiled a list of the 23

known elements

1800’s explosion of known number of elements

due to technology advancements

Organizing the Elements

Electricity & Spectrometers

Industrial Revolution

Chemists used the properties of elements to sort them into groups.

In 1829 J. W. Dobereiner arranged elements into triads – groups of three elements with similar properties

One element in each triad had properties intermediate of the other two elements

History

1860 universal method established for accurately determining masses of elements

1864 John Newlands proposed an organization for the elements

“Law of Octaves” – when elements arranged by increasing mass their properties repeat every 8th element

Not generally accepted because it did not work for all elements, but correct dealing w/repeating pattern

By 1870 approximately 70 known elements

History

1869 Lothar Meyer & Dmitri Mendeleev each

showed a connection between mass &

properties

Mendeleev given credit because 1st & he went on to

demonstrate usefulness of his organization method

Arranged elements by increasing mass & similar

properties

Left blank spaces for future element discoveries

History & Periodic Law

1913 Henry Moseley arranged the known elements by increasing atomic number & similar properties

Modern table is based on Moseley’s arrangement

Medeleev “Father of the Periodic Table

“Periodic Law” – there is a periodic repeating pattern of chemical & physical properties of elements when arranged by increasing atomic #

2002 – 115 known elements

Modern Periodic Table

Columns called “Groups” or “Families”

Each group numbered 1-8 followed by an A or B

Rows called “Periods”

7 periods total, beginning with Hydrogen

“Representative Elements” – groups 1A - 8A,

called this because posses a wide range of

chemical and physical properties

Modern Periodic Table

“Transition Elements” – groups with a B, 1B – 8B

“IUPAC” System of numbering – 1-18

“International Union of Pure & Applied Chemistry”

Three main classifications for elements

Metals

Nonmetals

Metalloids

Areas of the Periodic Table of Elements

Alkali Earth Alkaline Earth Transition

Metals Metalloids

Halogens Nobel Gases Other

Nonmetals

Major Sections

Metals

Shiny when smooth & clean, solid at room temp.

Good conductors of heat & electricity

Ductile & Malleable

Most of A elements & all of B elements

All elements to left of staircase line

1A = “alkali metals” & 2A = “alkaline earth metals”

B elements called transition and inner transition

Inner divided into lanthanide & actinide series

Metals

Group IA or 1

All have 1 valence electron

+1 oxidation number

Very reactive, can corrode in air

Soft, malleable, and ductile

Good conductors of electricity

Lithium, Sodium, Potassium,

Rubidium, Cesium, and Francium

Li

Na

K

Rb

Cs

Fr

Alkali Metals

Metals

Group IIA or 2

All have 2 valence electrons

+2 oxidation Number

Reactive elements

Beryllium, Magnesium, Calcium, Strontium,

Barium, and Radium

Be

Mg

Ca

Sr

Ba

Ra

Alkaline Earth Metals

Transition Metals

Groups III B – VIII B or 3-13

Have 3 major areas:

Transition

Actinide Series

Lanthanide Series

+ oxidation numbers

Hg is only liquid at room temperature

Transition Metals

Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga

Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn

La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi

Ac Rf Db Sg Bh Hs Mt

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Metalloids B

Si

Sb Te

Po

Ge As • Have both properties of

metals and nonmetals

• Are semiconductors; can

conduct electricity on a

small scale

• Boron, Silicon, Germanium,

Arsenic, Antimony, Tellurium,

and Polonium

Metalloids

Also known as semimetals

Elements that are bordered by the stair-step line

on the periodic table

Elements that have physical and chemicals

properties of both metals and nonmetals

Nonmetals

Upper right side of the table

Usually gases or brittle dull looking solids

• All are gases at room temperature except Br, which

is a liquid

Poor conductors of heat and electricity

Groups IV A – VIIA, 4A – 8A (14-18)

Group 15 has 5 valence electrons, and a –3

oxidation number

Group 16 has 6 valence electrons, and a –2

oxidation number

C N O F

P S Cl

Se Br

I

At

Nonmetals

Group VII A or 17

Each contains 7 valence electrons

-1 oxidation number

Fluorine, Chlorine, Bromine, Iodine,

& Astatine

Called halogens, because they often produce a salt compound

Halogen comes from Greek “Halos” = salt and “Gen” = born

F

Cl

Br

I

At

Halogens

Nonmetals

Group VIII A or 18

Called Nobel or Inert Gases

All have 8 valence electrons, except

Helium only has 2

Helium, Neon, Argon, Krypton,

Xenon, and Radon

He

Ne

Ar

Kr

Xe

Rn

Nobel Gases

Classification of Elements Organization by electron configuration

Valence Electrons

–Atoms in same group have similar chemical properties because they have the same number of valence electrons (rep. elements V.E.’s = group number)

–Ex. in 1A all have 1 valence electron

Valence Electrons & Period

–Energy level of element’s valence electrons indicates the period (# electron shells)

–Ex. Ga = [Ar]4s23d104p1, in period 4

1s1

1s22s1

1s22s22p63s1

1s22s22p63s23p64s1

1s22s22p63s23p64s23d104p65s1

1s22s22p63s23p64s23d104p65s24d10 5p66s1

1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p67s1

H 1

Li 3

Na 11

K 19

Rb 37

Cs 55

Fr 87

Do you notice any similarity in these

configurations of the alkali metals?

Alkali metals all end in s1

Alkaline earth metals all end in s2

really should include He, but it fits better in a

different spot, since He has the properties of

the noble gases, and has a full outer level of

electrons.

s2 s1 Elements in the s - blocks

He

Transition Metals - d block

d1 d2 d3 s1

d5 d5 d6 d7 d8 s1

d10 d10

Note the change in configuration.

The P-block p1 p2 p3 p4 p5 p6

Kr

He 2

Ne 10

Ar 18

36

Xe 54

Rn 86

1s2

1s22s22p6

1s22s22p63s23p6

1s22s22p63s23p64s23d104p6

1s22s22p63s23p64s23d104p65s24d105p6

1s22s22p63s23p64s23d104p65s24d10

5p66s24f145d106p6

Do you notice any similarity in the

configurations of the noble gases?

F - block

Called the “inner transition elements”

f1 f5 f2 f3 f4

f6 f7 f8 f9 f10 f11 f12 f14

f13

Classification The s, p, d, f block elements

S-block = groups 1A & 2A, V.E.’s only in s

orbitals

P-block = groups 3A – 8A, contains elements

with filled & partially filled p orbitals

D-block elements = spans 10 groups, contains

the transition metals, filled or partially filled d

orbitals

F-block elements = spans 14 columns, contains

the inner transition elements, filled or partially filled

f orbitals

Classification

s, p, d, f blocks determines the shape of the periodic table of elements

As move through periods the principal energy levels increase, as does number of sublevels

Period 1 = s block elements

Periods 2 - 3 = s & p block elements

Periods 4 - 5 = s, p, d block elements

Periods 6 – 7= s, p, d, f block elements

Periodic Trends Atomic radius

Atomic size is defined by how closely an atom lies

to a neighboring atom

Metals – half the distance between adjacent nuclei

in a crystal of the element

Nonmetals – half distance between nuclei of

identical atoms that are chemically bonded together

Decrease in size as move left-to-right across

period

Increase in size as move down a group

} Radius

Atomic Size

Measure the Atomic Radius - this is half the distance between the two nuclei of a diatomic molecule.

Periodic Trends Ionic Radius

Atoms gain or lose electrons to form ions

“Ion” – atom or group of atoms with a + or – charge

Atoms lose electrons, form + ions, become smaller

Atoms gain electrons, form – ions, become larger

Increase as move down a group

For metals as move left-to-right decrease and starting in 5A nonmetals decrease as move left-to-right

Atomic Radii

Li

Na

K

Rb

Cs

Cl S P Si Al

Br Se As Ge Ga

I Te Sb Sn In

Tl Pb Bi

Mg

Ca

Sr

Ba

Be F O N C B

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

Atomic size and Ionic size increase

in these directions:

Periodic Trends

Ionization Energy

An electron must be removed from a

neutral atom to form a + ion, which requires

energy

Ionization Energy – energy required to

remove an electron from an atom

Increase as move left-to-right across a

period

Decrease as move down a group

1

2

3

4

5

6

1

2

3

4

5

6

Ionization Energies

7

Be

900

Al

578

Si

787

Ti

659

V

651

Cr

653

Mn

717

Fe

762

Co

760

Ni

737

Cu

746

Zn

906

Ga

579

Ge

762

Nb

652

Mo

684

Tc

702

Ag

731

Cd

868

In

558

Sn

709

Sb

834

Ta

761

W

770

Re

760

Hg

1007

Tl

589

Pb

716

Bi

703

N

1402

O

1314

F

1681

Cl

1251

C

1086

S

1000

Br

1140

I

1008

Na

496

K

419

Rb

403

Cs

376

Ba

503

Fr

--

Ra

509

H

1312

B

801

P

1012

As

947

Se

941

Ru

710

Rh

720

Pd

804

Te

869

Os

839

Ir

878

Pt

868

Au

890

Po

812

At

--

Period

Actinide series

Li

520

Ca

590

Sc

633

Sr

550

Y

600

Zr

640

Hf

659

Mg

738

La

538

Ac

490

Lanthanide series

*

*

y

y

Group 1

2

3 4 5 6 7 11 12

13 14 15 16 17

18

9

Ne

2081

Ar

1521

Kr

1351

Xe

1170

Rn

1038

He

2372

Rf

--

Db

--

Sg

--

Bh

--

Hs

--

Mt

--

Ce

534

Pr

527

Nd

533

Pm

536

Sm

545

Eu

547

Gd

592

Tb

566

Dy

573

Ho

581

Er

589

Tm

597

Yb

603

Lu

523

Th

587

Pa

570

U

598

Np

600

Pu

585

Am

578

Cm

581

Bk

601

Cf

608

Es

619

Fm

627

Md

635

No

642

Lr

--

Ds

--

Uub

--

Uut

--

Uuq

--

Uup

--

Uuu

--

Uuo

--

Mg

738

Symbol

First Ionization Energy

(kJ/mol)

8 10

Periodic Trends

Electronegativity

Indicates the relative ability of atoms to attract electrons in a chemical bond

In chemical bond, the atom with the greater electronegativity more strongly attracts the bonds electrons

Increases as move left-to-right

Decreases as move down a group

Measured in units called Pauling's

1

2

3

4

5

6

1

2

3

4

5

6

Electronegativities

7

Be

1.5

Al

1.5

Si

1.8

Ti

1.5

V

1.6

Cr

1.6

Mn

1.5

Fe

1.8

Co

1.8

Ni

1.8

Cu

1.9

Zn

1.7

Ga

1.6

Ge

1.8

Nb

1.6

Mo

1.8

Tc

1.9

Ag

1.9

Cd

1.7

In

1.7

Sn

1.8

Sb

1.9

Ta

1.5

W

1.7

Re

1.9

Hg

1.9

Tl

1.8

Pb

1.8

Bi

1.9

1.5 - 1.9

N

3.0

O

3.5

F

4.0

Cl

3.0

3.0 - 4.0

C

2.5

S

2.5

Br

2.8

I

2.5

2.5 - 2.9

Na

0.9

K

0.8

Rb

0.8

Cs

0.7

Ba

0.9

Fr

0.7

Ra

0.9

Below 1.0

H

2.1

B

2.0

P

2.1

As

2.0

Se

2.4

Ru

2.2

Rh

2.2

Pd

2.2

Te

2.1

Os

2.2

Ir

2.2

Pt

2.2

Au

2.4

Po

2.0

At

2.2

2.0 - 2.4

Period

Actinides: 1.3 - 1.5

Li

1.0

Ca

1.0

Sc

1.3

Sr

1.0

Y

1.2

Zr

1.4

Hf

1.3

Mg

1.2

La

1.1

Ac

1.1

1.0 - 1.4

Lanthanides: 1.1 - 1.3

*

*

y

y

1A

2A

3B 4B 5B 6B 7B 1B 2B

3A 4A 5A 6A 7A

8A

8B

The arrows indicate the trend:

Ionization energy and Electronegativity

INCREASE in these directions

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 Points

Symbol

Melting point oC

> 3000 oC 2000 - 3000 oC

La

920

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

Symbol

Density 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

Summary of Periodic Trends

Ionic size (cations) Ionic size (anions)

decreases decreases

Shielding is constant

Atomic radius decreases

Ionization energy increases

Electronegativity increases

Nuclear charge increases

Nu

cle

ar

ch

arg

e in

cre

as

es

Sh

ield

ing

in

cre

as

es

Ato

mic

ra

diu

s in

cre

as

es

Ion

ic s

ize

in

cre

as

es

Ion

iza

tio

n e

ne

rgy d

ec

rea

se

s

Ele

ctr

on

eg

ati

vit

y d

ecre

ases

1A

2A 3A 4A 5A 6A 7A

0

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

*

W

Hydrogen

Alkali metals

Alkaline Earth Metals

Coinage Metals

Other Transition Elements

Metalloids

(B, Si, Ge, As, Sb, Te, At)

Halogens

Noble Gases

Other Nonmetals

Lanthanides

Actinides

Other metals

W

*