Modern Periodic Table

Last Updated : 17 Apr, 2026

The Modern Periodic Table is a systematic arrangement of elements based on their atomic number. It is based on the modern periodic law, which states that the physical and chemical properties of elements are periodic functions of their atomic numbers. This table was developed after the modification of earlier periodic tables to remove their limitations. The elements in the modern periodic table are arranged in rows called periods and columns called groups. Elements in the same group have similar chemical properties.

periodic_table

List of Periodic Table Elements

The elements listed are arranged according to the increasing order of atomic number.

Elements in Periodic Table with Atomic Mass

Atomic NumberChemical Element NameSymbolAtomic Mass (amu)
1HydrogenH1.0079
2HeliumHe4.0026
3LithiumLi6.941
4BerylliumBe9.0122
5BoronB10.811
6CarbonC12.0107
7NitrogenN14.0067
8OxygenO15.9994
9FluorineF18.9984
10NeonNe20.1797
11SodiumNa22.9897
12MagnesiumMg24.305
13AluminumAl26.9815
14SiliconSi28.0855
15PhosphorusP30.9738
16SulfurS32.065
17ChlorineCl35.453
18ArgonAr39.948
19PotassiumK39.0983
20CalciumCa40.078
21ScandiumSc44.9559
22TitaniumTi47.867
23VanadiumV50.9415
24ChromiumCr51.9961
25ManganeseMn54.938
26IronFe55.845
27CobaltCo58.9332
28NickelNi58.6934
29CopperCu63.546
30ZincZn65.39
31GalliumGa69.723
32GermaniumGe72.64
33ArsenicAs74.9216
34SeleniumSe78.96
35BromineBr79.904
36KryptonKr83.798
37RubidiumRb85.4678
38StrontiumSr87.62
39YttriumY88.906
40ZirconiumZr91.224
41NiobiumNb92.906
42MolybdenumMo95.94
43TechnetiumTc98
44RutheniumRu101.07
45RhodiumRh102.91
46PalladiumPd106.42
47SilverAg107.87
48CadmiumCd112.411
49IndiumIn114.82
50TinSn118.71
51AntimonySb121.76
52TelluriumTe127.6
53IodineI126.9045
54XenonXe131.293
55CesiumCs132.91
56BariumBa137.327
57LanthanumLa138.91
58CeriumCe140.12
59PraseodymiumPr140.9077
60NeodymiumNd144.24
61PromethiumPm145
62SamariumSm150.36
63EuropiumEu151.964
64GadoliniumGd157.25
65TerbiumTb158.9253
66DysprosiumDy162.5
67HolmiumHo164.9303
68ErbiumEr167.259
69ThuliumTm168.9342
70YtterbiumYb173.04
71LutetiumLu174.967
72HafniumHf178.49
73TantalumTa180.9479
74TungstenW183.84
75RheniumRe186.207
76OsmiumOs190.23
77IridiumIr192.22
78PlatinumPt195.08
79GoldAu196.97
80MercuryHg200.59
81ThalliumTl204.3833
82LeadPb207.2
83BismuthBi208.9804
84PoloniumPo209
85AstatineAt210
86RadonRn222
87FranciumFr223
88RadiumRa226
89ActiniumAc227
90ThoriumTh232.0381
91ProtactiniumPa231.0359
92UraniumU238.0289
93NeptuniumNp237
94PlutoniumPu244
95AmericiumAm243
96CuriumCm247
97BerkeliumBk247
98CaliforniumCf251
99EinsteiniumEs252
100FermiumFm257
101MendeleviumMd258
102NobeliumNo259
103LawrenciumLr262
104RutherfordiumRf267
105DubniumDb268
106SeaborgiumSg269
107BohriumBh270
108HassiumHs269
109MeitneriumMt277
110DarmstadtiumDs281
111RoentgeniumRg282
112CoperniciumCn285
113NihoniumNh286
114FleroviumFl290
115MoscoviumMc290
116LivermoriumLv293
117TennessineTs294
118OganessonOg294

Important Terms in Periodic Table

Terms

Description

Atomic Number

The number of protons that constitutes an element's nucleus is called its Atomic Number (Z). e.g. Carbon contains 6 protons then, so its atomic number must be 6 only. 

Atomic Mass

It is defined as the average mass of the atoms of an element. It is measured on the basis of the relative natural abundance of the isotopes of the element. Atomic mass is also termed Atomic Weight (A). It is measured in the atomic mass unit (amu).

Period

The horizontal rows from left to right in a periodic table are called Periods. There are a total of 7 periods in the periodic table. Elements in a period are arranged based on increasing atomic number. Properties change gradually, not similarly..

Group

The vertical columns from top to bottom in a periodic table are called Groups. There is a total of 18 groups in the periodic table. The elements are arranged vertically due to their similarities in properties, as they have the same number of valence electrons in them.

Symbol of an Element

A symbol is a notion that is used to represent a chemical element using a letter or a combination of letters. e.g. The chemical symbol of Carbon is C, while Fe is used for Iron and so on.

Classification of Elements in Periodic Table

The 118 elements are arranged in 7 periods and 18 groups as shown above. Further, the elements are divided into different blocks.

BlockElements IncludedLast Electron Subshell Filled
s-blockGroup 1 (Alkali Metals)s-subshell
Group 2 (Alkaline Earth Metals)
p-blockGroup 13 (Boron Family)p-subshell
Group 14 (Carbon Family)
Group 15 (Nitrogen Family)
Group 16 (Oxygen Family)


Group 17 (Halogen Family)

Group 18 (Noble Gas Family)

d-blockGroups 3 to 12 (Transition Elements)d-subshell
f-blockLanthanides (Rare Earth Elements)f-subshell
Actinides

Mendeleev Periodic Table

Dmitri Mendeleev proposed the periodic table in 1869 to arrange elements in a systematic way based on their properties. He arranged elements in order of increasing atomic mass and grouped them according to similarities in their chemical properties.

In this table, elements were placed in rows called periods and columns called groups. Elements in the same group showed similar chemical behaviour.

Mendeleev Periodic Table of Elements
  • Each group was divided into A (main elements) and B (transition elements).
  • He left gaps for undiscovered elements and predicted their properties correctly.
  • A regular pattern was observed in the formation of oxides and hydrides.
  • The position of hydrogen was not fixed as it shows properties of two groups.
  • Isotopes could not be placed properly since they have different atomic masses but similar properties.
  • Some elements were not arranged in increasing atomic mass order (e.g., Co and Ni).
  • Proper arrangement of transition elements was not given.
  • It did not explain the internal structure of atoms
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