Chemical Elements

What are Chemical Elements?

Chemical elements simply called elements in the periodic table are materials that cannot be broken down or changed into another substance using any chemical process. They are the basic building blocks of matter and are present in all molecules or chemical compounds. The list of chemical elements in the periodic table now extends up to 118. The name, symbol, atomic number, atomic weight, and electron per shell for all 118 elements on the periodic table is given below the picture,

The periodic table classification of these 118 chemical elements (metals, non-metals, metalloids) is based on the modern periodic law. Elements in the periodic table participate in different types of chemical bonding such as ionic bonding, covalent bonding, or metallic bonding to form substances.

Classification of Chemical Elements

Mendeleev in 1867 first time attempted to classify chemical elements according to their atomic weight.

The post-Mendeleev developments and in order to remove the defects of the Mendeleev periodic table a number of tables have been suggested for the classification of chemical elements. All these tables are arranged in the increasing order of their atomic numbers.

Four types of chemical elements are found on the periodic table depending on the nature of the atomic orbitals in which the last electrons enter. These are,

• s-block elements
• p-block elements
• d-block elements
• f-block elements

All these 118 chemical elements of the periodic table are classified into four types by Bohr on the basis of their electronic configuration. They are grouped into four classes depending on the number of incomplete shells of electrons in the atom.

• Inert gases or noble gases
• Representative or normal elements
• Transition elements
• Inner transition elements or f-block elements

Inert Gases

The lack of chemical reactivity of noble gases was the reason to call them inert. The atoms of these chemical elements have completely filled s or p-subshells. They have very little tendency to form chemical compounds due to the highly stable ns²np⁶ configuration or valence shell configuration (except He 1s²).

Representative or Normal Elements

The representative or normal chemical elements contain some metals, all non-metals, and metalloids. They can be divided into two groups,

• s-block elements
• p-block elements

s-block Chemical Elements

The outermost electronic configuration of s-block chemical elements varies from ns¹ to ns². The members of s-block elements lie on the extreme left of the periodic table.

Alkali metals and alkaline earth metals are included in this class. They are extremely electropositive in nature.

p-block Chemical Elements

The outer electronic configuration of the atoms of p-block elements varies from ns²np¹ to ns²np⁶.

Non-metals, metalloids, and inert gases are included in these categories. These chemical elements lie on the extreme right of the periodic table.

Transition Metals

The outermost two shells in transition elements are incomplete. They are placed between s- and p-block chemical elements. Atoms of these elements have (n-1)d^{1 to 10}ns^{o or 1 or 2} general electronic configurations.

Inner Transition Elements

The inner transition elements are those elements whose 4f and 5f orbitals are progressively filled by electrons. Therefore, f block elements are also called inner transition chemical elements. They formed two series such as lanthanoids and actinoids.

The atoms of these chemical elements have three incomplete outer shells. These three incomplete shells are outer ns orbital, (n-1)d orbital, and (n-2)f orbital. The general electronic configuration of inner transition chemical elements are (n-2)f^{1 to 14}(n-1)d^{0 or 1 or 2}ns².

List of Chemical Elements

The list of 118 chemical elements with name, atomic number, symbol, atomic weight, electronic configuration, and discovery is given below the table,

List of chemical elements
Element			Atomic weight	Period	Group	Electronic configuration	Block	Discovered by
Atomic number	Symbol	Name
1	H	Hydrogen	1.008	1	1	1s1	s-block	Henry Cavendish
2	He	Helium	4.0026	1	18	1s2	p-block	Sir William Ramsay and independently by Per Teodor Cleve and Nils Abraham Langlet
3	Li	Lithium	6.94	2	1	[He] 2s1	s-block	Johan August Arfvedson
4	Be	Beryllium	9.0122	2	2	[He] 2s2	s-block	Nicholas Louis Vauquelin
5	B	Boron	10.81	2	13	[He] 2s22p1	p-block	Louis-Josef Gay-Lussac and Louis-Jacques Thénard and Humphry Davy
6	C	Carbon	12.011	2	14	[He] 2s22p2	p-block
7	N	Nitrogen	14.007	2	15	[He] 2s22p3	p-block	Daniel Rutherford
8	O	Oxygen	15.999	2	16	[He] 2s22p4	p-block	Joseph Priestley and independently by Carl Wilhelm Scheele
9	F	Fluorine	18.998	2	17	[He] 2s22p5	p-block	Henri Moissan
10	Ne	Neon	20.180	2	18	[He] 2s22p6	p-block	Sir William Ramsay and Morris Travers
11	Na	Sodium	22.990	3	1	[Ne] 3s1	s-block	Humphry Davy
12	Mg	Magnesium	24.305	3	2	[Ne] 3s2	s-block	Joseph Black
13	Al	Aluminum	26.982	3	13	[Ne] 3s23p1	p-block	Hans Oersted
14	Si	Silicon	28.085	3	14	[Ne] 3s23p2	p-block	Jöns Jacob Berzelius
15	P	Phosphorus	30.974	3	15	[Ne] 3s23p3	p-block	Hennig Brandt
16	S	Sulfur	32.06	3	16	[Ne] 3s23p4	p-block
17	Cl	Chlorine	35.45	2	17	[Ne] 3s23p5	p-block	Carl Wilhelm Scheele
18	Ar	Argon	39.95	3	18	[Ne] 3s23p6	p-block	Lord Rayleigh and Sir William Ramsay
19	K	Potassium	39.098	4	1	[Ar] 4s1	s-block	Humphry Davy
20	Ca	Calcium	40.078	4	2	[Ar] 4s2	s-block	Humphry Davy
21	Sc	Scandium	44.956	4	3	[Ar] 3d14s2	d-block	Lars Frederik Nilson
22	Ti	Titanium	47.867	4	4	[Ar] 3d24s2	d-block	William Gregor
23	V	Vanadium	50.942	4	5	[Ar] 3d34s2	d-block	Andrés Manuel del Rio
24	Cr	Chromium	51.996	4	6	[Ar] 3d54s1	d-block	Nicholas Louis Vauquelin
25	Mn	Manganese	54.938	4	7	[Ar] 3d54s2	d-block	Johan Gottlieb Gahn
26	Fe	Iron	55.845	4	8	[Ar] 3d64s2	d-block
27	Co	Cobalt	58.933	4	9	[Ar] 3d74s2	d-block	Georg Brandt
28	Ni	Nickel	58.693	4	10	[Ar] 3d84s2	d-block	Axel Fredrik Cronstedt
29	Cu	Copper	63.546	4	11	[Ar] 3d104s1	d-block
30	Zn	Zinc	65.38	4	12	[Ar] 3d104s2	d-block	Andreas Marggraf
31	Ga	Gallium	69.723	4	13	[Ar] 3d104s24p1	p-block	Paul-Émile Lecoq de Boisbaudran
32	Ge	Germanium	72.630	4	14	[Ar] 3d104s24p2	p-block	Clemens Winkler
33	As	Arsenic	74.922	4	15	[Ar] 3d104s24p3	p-block	Albertus Magnus
34	Se	Selenium	78.971	4	16	[Ar] 3d104s24p4	p-block	Jöns Jacob Berzelius
35	Br	Bromine	79.904	4	17	[Ar] 3d104s24p5	p-block	Antoine-Jérôme Balard and Carl Löwig in Heidelberg
36	Kr	Krypton	83.798	4	18	[Ar] 3d104s24p6	p-block	Sir William Ramsay and Morris Travers
37	Rb	Rubidium	85.468	5	1	[Kr] 5s1	s-block	Gustav Kirchhoff and Robert Bunsen
38	Sr	Strontium	87.62	5	2	[Kr] 5s2	s-block	Adair Crawford
39	Y	Yttrium	88.906	5	3	[Kr] 4d15s2	d-block	Johan Gadolin
40	Zr	Zirconium	91.224	5	4	[Kr] 4d25s2	d-block	Martin Heinrich Klaproth
41	Nb	Niobium	92.906	5	5	[Kr] 4d35s2	d-block	Charles Hatchett
42	Mo	Molybdenum	95.95	5	6	[Kr] 4d55s1	d-block	Peter Jacob Hjelm
43	Tc	Technetium	97	5	7	[Kr] 4d55s2	d-block	Carlo Perrier and Emilio Segrè
44	Ru	Ruthenium	101.07	5	8	[Kr] 4d75s1	d-block	Karl Karlovich Klaus
45	Rh	Rhodium	102.91	5	9	[Kr] 4d85s1	d-block	William Hyde Wollaston
46	Pd	Palladium	106.42	5	10	[Kr] 4d105s0	d-block	William Hyde Wollaston
47	Ag	Silver	107.87	5	11	[Kr] 4d105s1	d-block
48	Cd	Cadmium	112.41	5	12	[Kr] 4d105s2	d-block	Friedrich Stromeyer
49	In	Indium	114.82	5	13	[Kr] 4d105s25p1	p-block	Ferdinand Reich and Hieronymous Richter
50	Sn	Tin	118.71	5	14	[Kr] 4d105s25p2	p-block
51	Sb	Antimony	121.76	5	15	[Kr] 4d105s25p3	p-block
52	Te	Tellurium	127.60	5	16	[Kr]4d105s25p4	p-block	Franz-Joseph Müller von Reichenstein
53	I	Iodine	126.90	5	17	[Kr] 4d105s25p5	p-block	Bernard Courtois
54	Xe	Xenon	131.29	5	18	[Kr] 4d105s25p6	p-block	Sir William Ramsay and Morris Travers
55	Cs	Caesium	132.91	6	1	[Xe] 6s1	s-block	Gustav Kirchhoff and Robert Bunsen
56	Ba	Barium	137.33	6	2	[Xe] 6s2	s-block	Humphry Davy
57	La	Lanthanum	138.91	6	3	[Xe] 5d16s2	d-block	Carl Gustav Mosander
58	Ce	Cerium	140.12	6	n/a	[Xe] 4f15d16s2	f-block	Jöns Jacob Berzelius and Wilhelm Hisinger
59	Pr	Praseodymium	140.91	6	n/a	[Xe] 4f36s2	f-block	Carl Auer von Welsbach
60	Nd	Neodymium	144.24	6	n/a	[Xe] 4f46s2	f-block	Carl Auer von Welsbach
61	Pm	Promethium	145	6	n/a	[Xe] 4f56s2	f-block	Jacob .A. Marinsky, Lawrence E. Glendenin, and Charles D. Coryell
62	Sm	Samarium	150.36	6	n/a	[Xe]4f66s2	f-block	Paul-Émile Lecoq de Boisbaudran
63	Eu	Europium	151.96	6	n/a	[Xe] 4f76s2	f-block	Eugène-Anatole Demarçay
64	Gd	Gadolinium	157.25	6	n/a	[Xe] 4f75d16s2	f-block	Jean Charles Galissard de Marignac
65	Tb	Terbium	158.93	6	n/a	[Xe] 4f96s2	f-block	Carl Gustav Mosander
66	Dy	Dysprosium	162.50	6	n/a	[Xe] 4f106s2	f-block	Paul-Émile Lecoq de Boisbaudran
67	Ho	Holmium	164.93	6	n/a	[Xe] 4f116s2	f-block	Per Teodor Cleve and independently by Marc Delafontaine and Louis Soret
68	Er	Erbium	167.26	6	n/a	[Xe] 4f126s2	f-block	Carl Gustav Mosander
69	Tm	Thulium	168.93	6	n/a	[Xe]4f136s2	f-block	Per Teodor Cleve
70	Yb	Ytterbium	173.05	6	n/a	[Xe] 4f146s2	f-block	Jean Charles Galissard de Marignac
71	Lu	Lutetium	174.97	6	n/a	[Xe] 4f145d16s2	f-block	Georges Urbain and independently by Charles James
72	Hf	Hafnium	178.49	6	4	[Xe] 4f145d26s2	d-block	George Charles de Hevesy and Dirk Coster
73	Ta	Tantalum	180.95	6	5	[Xe] 4f145d36s2	d-block	Anders Gustav Ekeberg
74	W	Tungsten	183.84	6	6	[Xe] 4f145d46s2	d-block	Juan and Fausto Elhuyar
75	Re	Rhenium	186.21	6	7	[Xe] 4f145d56s2	d-block	Walter Noddack, Ida Tacke and Otto Berg
76	Os	Osmium	190.23	6	8	[Xe] 4f145d66s2	d-block	Smithson Tennant
77	Ir	Iridium	192.22	6	9	[Xe] 4f145d76s2	d-block	Smithson Tennant
78	Pt	Platinum	195.08	6	10	[Xe] 4f145d96s1	d-block
79	Au	Gold	196.97	6	11	[Xe] 4f145d106s1	d-block
80	Hg	Mercury	200.59	6	12	[Xe] 4f145d106s2	d-block
81	Tl	Thallium	204.38	6	13	[Xe] 4f145d106s26p1	p-block	William Crookes
82	Pb	Lead	207.2	6	14	[Xe] 4f145d106s26p2	p-block
83	Bi	Bismuth	208.98	6	15	[Xe] 4f145d106s26p3	p-block
84	Po	Polonium	209	6	16	[Xe] 4f145d106s26p4	p-block	Marie Curie
85	At	Astatine	210	6	17	[Xe] 4f145d106s26p5	p-block	Dale R. Corson, Kenneth Ross MacKenzie, Emilio Segrè
86	Rn	Radon	222	6	18	[Xe] 4f145d106s26p6	p-block	Friedrich Ernst Dorn
87	Fr	Francium	223	7	1	[Rn] 7s1	s-block	Marguerite Perey
88	Ra	Radium	226	7	2	[Rn] 7s2	s-block	Pierre and Marie Curie
89	Ac	Actinium	227	7	3	[Rn] 6d17s2	d-block	Andrew Debierne
90	Th	Thorium	232.04	7	Actinides	[Rn] 6d27s2	f-block	Jöns Jacob Berzelius
91	Pa	Protactinium	231.04	7	Actinides	[Rn] 5f26d17s2	f-block	Kasimir Fajans and Otto Göhring
92	U	Uranium	238.03	7	Actinides	[Rn] 5f36d17s2	f-block	Martin Heinrich Klaproth
93	Np	Neptunium	[237]	7	Actinides	[Rn] 5f46d17s2	f-block	Edwin McMillan and Philip Abelson
94	Pu	Plutonium	[244]	7	Actinides	[Rn] 5f67s2	f-block	Glenn Seaborg and colleagues
95	Am	Americium	[243]	7	Actinides	[Rn] 5f77s2	f-block	Glenn Seaborg and colleagues
96	Cm	Curium	[247]	7	Actinides	[Rn] 5f76d17s2	f-block	Glenn Seaborg and colleagues
97	Bk	Berkelium	[247]	7	Actinides	[Rn] 5f97s2	f-block	Stanley Thompson, Albert Ghiorso, and Glenn Seaborg
98	Cf	Californium	[251]	7	Actinides	[Rn] 5f107s2	f-block	Stanley Thompson, Kenneth Street, Jr., Albert Ghiorso, and Glenn Seaborg
99	Es	Einsteinium	[252]	7	Actinides	[Rn] 5f117s2	f-block	Albert Ghiorso and colleagues
100	Fm	Fermium	[257]	7	Actinides	[Rn] 5f127s2	f-block	Albert Ghiorso and colleagues
101	Md	Mendelevium	[258]	7	Actinides	[Rn] 5f137s2	f-block	Albert Ghiorso and colleagues
102	No	Nobelium	[259]	7	Actinides	[Rn] 5f147s2	f-block	Georgy Flerov and colleagues and independently by Albert Ghiorso and colleagues
103	Lw	Lawrencium	[266]	7	Actinides	[Rn] 5f147s27p1	f-block	Georgy Flerov and colleagues and independently by Albert Ghiorso and colleagues
104	Rf	Rutherfordium	[267]	7	4	[Rn] 5f146d27s2	d-block	Georgy Flerov and colleagues and independently by Albert Ghiorso and colleagues
105	Db	Dubnium	[268]	7	5	[Rn] 5f146d37s2	d-block	Scientists at both Berkeley, California, USA, and Dubna, near Moscow, Russia
106	Sg	Seaborgium	[269]	7	6	[Rn] 5f146d47s2	d-block	Albert Ghiorso and colleagues
107	Bh	Bohrium	[269]	7	7	[Rn] 5f146d57s2	d-block	Peter Armbruster, Gottfried Münzenberg and colleagues
108	Hs	Hassium	[269]	7	8	[Rn] 5f146d67s2	d-block	Peter Armbruster, Gottfried Münzenberg
109	Mt	Meitnerium	[278]	7	9	[Rn] 5f146d77s2	d-block	Peter Armbruster, Gottfried Münzenberg and colleagues
110	Ds	Darmstadtium	[281]	7	10	[Rn] 5f146d97s1	d-block	Sigurd Hofmann, Peter Armbruster and Gottfried Münzenberg
111	Rg	Roentgenium	[282]	7	11	[Rn] 5f146d107s1	d-block	Peter Armbruster and Gottfried Münzenberg
112	Cn	Copernicium	[285]	7	12	[Rn] 5f146d107s2	d-block	Sigurd Hofmann and colleagues
113	Nh	Nihonium	[286]	7	13	[Rn] 5f146d107s27p1	p-block	Scientists from RIKEN in Japan
114	Fl	Flerovium	[289]	7	14	[Rn] 5f146d107s27p2	p-block	Scientists from JINS and LLNL
115	Mc	Moscovium	[290]	7	15	[Rn] 5f146d107s27p3	p-block	Scientists from JINS, LLNL and ORNL
116	Lv	Livermorium	[293]	7	16	[Rn] 5f146d107s27p4	p-block	Scientists from JINS and LLNL
117	Ts	Tennessine	[294]	7	17	[Rn] 5f146d107s27p5	p-block	Scientists from JINS, LLNL and ORNL
118	Og	Oganesson	[294]	7	18	[Rn] 5f146d107s27p6	p-block	Scientists from JINS and LLNL