Periodic Table

4th Lykeion of Corfu

Class A

Dobereiner 1829

3-ades of elements withsimilar properties

Cl, Br, I

Ca, Sr, Ba

etc.

Newlands 1863

Rule of “Octaves”

7Li 9Be 10B 12C 14N 16O 19F 20Ne23Na 24Mg 27Al 28Si 31P 32S 35Cl 36Ar39K 40Ca ……

1 52 3 4 6 7

8

Newlands

If all the elements be arranged in order of their atomic weights a periodic repetition of properties is obtained." - Mendeleyev

Dmitri Mendeleev

Lothar Meyer1869

Known elements when the Mendeleev’s table established

127Ι 129Te

?

?

1874 -1885

Discovery of Gallium (Ga), Germanium (Ge) και Scandium (Sc)

Their properties were almost expectable !

Henry Moseley 1913

The elements may be arranged in order of their Atomic Numbers and not to their Atomic weights

“ There is in the atom a fundamental quantity which increases by regular steps as we pass from each element to the next. This quantity can only be the charge on the central positive nucleus.”

7Li 9Be 10B 12C 14N 16O 19F 20Ne3Li 4Be 5B 6C 7N 8O 9F 10Ne

O16

8

Mass Number

Atomic Number

ΙΑ ΙΙΑ ΙΙΙΑ ΙVΑ VΑ VIΑ VIIΑ VIIIΑ

ΙΙΙB ΙVB VB VIB VIIBVIIIB ΙB ΙΙB

1st

2nd

3rd

4th

5th

6th

7th

Contemporary P.T.

Groups : The VERTICAL columns

Elements within a group have similar properties

Group ΙΑ ( 1st ) or ALKALI METALS

3Li K2 L1

11Na K2 L8 M1

19K K2 L8 M8 N1

37Rb K2 L8 M18 N8 O1

55Cs K2 L8 M18 N18 O8 P1

87Fr K2 L8 M18 N32 O18 P8 Q1

Group ΙIΑ ( 2nd ) or ALKALINE EARTH METALS

4Be K2 L2

12Mg K2 L8 M2

20Ca K2 L8 M8 N2

38Sr K2 L8 M18 N8 O2

56Ba K2 L8 M18 N18 O8 P2

87Ra K2 L8 M18 N32 O18 P8 Q2

Group VΙIΑ ( 17th ) or HALOGENS

9F K2 L7

17Cl K2 L8 M7

35Br K2 L8 M18 N7

53I K2 L8 M18 N18 O7

85At K2 L8 M18 N32 O18 P7

Group VIΙIΑ or (O) or 18th NOBLE GASES

10Ne K2 L8

18Ar K2 L8 M8

36Kr K2 L8 M18 N8

54Xe K2 L8 M18 N18 O8

86Rn K2 L8 M18 N32 O18 P8

2He K2

Transition Metals

21Sc K2 L8 M9 N2 22Ti K2 L8 M10 N2 ….

39Y K2 L8 M18 N9 O2 40Zr K2 L8 M18 N10 O2 ….

Rare Earths ( Lanthanides & Actinides )

The horizontal rows of the periodic table are called PERIODS.

37Rb K2 L8 M18 N8 O1

38Sr K2 L8 M18 N8 O2

39Y K2 L8 M18 N9 O2

………………

Periodic TableAlkali Metals

Alkaline Earth Metals

Transition Metals

Halogens

Noble Gases

Lanthanides & Actinides

Main Groups

Main Groups

Period Elements Atomic Number (Z)

From to

1st 2

2nd 8

3rd 8

4th 18

5th 18

6th 32

7th ….

1 2

3 10

11 18

19 36

37 54

55 86

87