Modern Periodic Table

What is the Periodic Table?

The other name for Periodic Table is Mendeleev’s Table that contains all chemical elements that exist on Earth. The table was proposed in the year 1869 where elements were arranged based on their properties. Although many more elements were in existence prior to that as well, it was the most organized form for scientists where new elements are added as soon as they are discovered.

The structure of the table is quite significant that holds 117 chemical elements in a very distinct order based on their chemical properties. Out of all, 94 elements are given by nature and 24 has been made synthetically by scientists. You can quickly distinguish between metals and non-metals by looking at the table. Metals are placed on the left-hand side and non-metals are placed at the right-hand side.

Further, atoms are arranged based on their increasing atomic numbers in rows and columns. There is a unique symbol for each chemical element and their properties are also different. Based on the properties, the chemical elements are divided into periods, blocks, and groups. Groups are arranged in the vertical rows and columns are arranged in the horizontal rows. And there are groups in the periodic table like – s-block, p-block, d-block, and the f-block.

The Periodic table of elements

The location of the element within a periodic table is highly important based on properties of chemical elements in rows, columns, or blocks. This is easy to predict the properties of an element based on its location. However, trends will differ in the periodic table once you move from the vertical direction to the horizontal along the table.

The trends of groups can be explained by common electronic configurations in their valence cells. They are usually explained on the basis of electronegativity, ionization energy or the atomic radii etc. For each chemical element, there is proton, electrons, and neutrons too.

When moving from left to the right, the atomic radii would decrease and the ionization energy tends to increase. At the same time, when moving from left to the right, the electronic affinity and electronegativity will increase.

Atomic No	Atomic Mass	Chemical Element Name	Symbol	Discovery (Year)	Group
1	1.0079	Hydrogen	H	1776	1
2	4.0026	Helium	He	1895	18
3	6.941	Lithium	Li	1817	1
4	9.0122	Beryllium	Be	1797	2
5	10.811	Boron	B	1808	13
6	12.0107	Carbon	C	Ancient	14
7	14.0067	Nitrogen	N	1772	15
8	15.9994	Oxygen	O	1774	16
9	18.9984	Fluorine	F	1886	17
10	20.1797	Neon	Ne	1898	18
11	22.9897	Sodium	Na	1807	1
12	24.305	Magnesium	Mg	1755	2
13	26.9815	Aluminum	Al	1825	13
14	28.0855	Silicon	Si	1824	14
15	30.9738	Phosphorus	P	1669	15
16	32.065	Sulfur	S	Ancient	16
17	35.453	Chlorine	Cl	1774	17
18	39.948	Argon	Ar	1894	18
19	39.0983	Potassium	K	1807	1
20	40.078	Calcium	Ca	1808	2
21	44.9559	Scandium	Sc	1879	3
22	47.867	Titanium	Ti	1791	4
23	50.9415	Vanadium	V	1830	5
24	51.9961	Chromium	Cr	1797	6
25	54.938	Manganese	Mn	1774	7
26	55.845	Iron	Fe	Ancient	8
27	58.9332	Cobalt	Co	1735	9
28	58.6934	Nickel	Ni	1751	10
29	63.546	Copper	Cu	Ancient	11
30	65.39	Zinc	Zn	Ancient	12
31	69.723	Gallium	Ga	1875	13
32	72.64	Germanium	Ge	1886	14
33	74.9216	Arsenic	As	Ancient	15
34	78.96	Selenium	Se	1817	16
35	79.904	Bromine	Br	1826	17
36	83.8	Krypton	Kr	1898	18
37	85.4678	Rubidium	Rb	1861	1
38	87.62	Strontium	Sr	1790	2
39	88.9059	Yttrium	Y	1794	3
40	91.224	Zirconium	Zr	1789	4
41	92.9064	Niobium	Nb	1801	5
42	95.94	Molybdenum	Mo	1781	6
43	98	Technetium	Tc	1937	7
44	101.07	Ruthenium	Ru	1844	8
45	102.9055	Rhodium	Rh	1803	9
46	106.42	Palladium	Pd	1803	10
47	107.8682	Silver	Ag	Ancient	11
48	112.411	Cadmium	Cd	1817	12
49	114.818	Indium	In	1863	13
50	118.71	Tin	Sn	Ancient	14
51	121.76	Antimony	Sb	Ancient	15
52	127.6	Tellurium	Te	1783	16
53	126.9045	Iodine	In	1811	17
54	131.293	Xenon	Xe	1898	18
55	132.9055	Cesium	Cs	1860	1
56	137.327	Barium	Ba	1808	2
57	138.9055	Lanthanum	La	1839	3
58	140.116	Cerium	Ce	1803	101
59	140.9077	Praseodymium	Pr	1885	101
60	144.24	Neodymium	Nd	1885	101
61	145	Promethium	Pm	1945	101
62	150.36	Samarium	Sm	1879	101
63	151.964	Europium	Eu	1901	101
64	157.25	Gadolinium	Gd	1880	101
65	158.9253	Terbium	Tb	1843	101
66	162.5	Dysprosium	Dy	1886	101
67	164.9303	Holmium	Ho	1867	101
68	167.259	Erbium	Er	1842	101
69	168.9342	Thulium	Tm	1879	101
70	173.04	Ytterbium	Yb	1878	101
71	174.967	Lutetium	Lu	1907	101
72	178.49	Hafnium	Hf	1923	4
73	180.9479	Tantalum	Ta	1802	5
74	183.84	Tungsten	W	1783	6
75	186.207	Rhenium	Re	1925	7
76	190.23	Osmium	Os	1803	8
77	196.9665	Iridium	Ir	Ancient	11
78	192.217	Platinum	Pt	1803	9
79	195.078	Gold	Au	1735	10
80	200.59	Mercury	Hg	Ancient	12
81	204.3833	Thallium	Tl	1861	13
82	207.2	Lead	Pb	Ancient	14
83	208.9804	Bismuth	Bi	Ancient	15
84	209	Polonium	Po	1898	16
85	210	Astatine	At	1940	17
86	222	Radon	Rn	1900	18
87	223	Francium	Fr	1939	1
88	226	Radium	Ra	1898	2
89	227	Actinium	Ac	1899	3
90	232.0381	Thorium	Th	1829	102
91	231.0359	Protactinium	Pa	1913	102
92	238.0289	Uranium	U	1789	102
93	237	Neptunium	Np	1940	102
94	244	Plutonium	Pu	1940	102
95	243	Americium	Am	1944	102
96	247	Curium	Cm	1944	102
97	247	Berkelium	Bk	1949	102
98	251	Californium	Cf	1950	102
99	252	Einsteinium	Es	1952	102
100	257	Fermium	Fm	1952	102
101	258	Mendelevium	Md	1955	102
102	259	Nobelium	No	1958	102
103	262	Lawrencium	Lr	1961	102
104	261	Rutherfordium	Rf	1964	4
105	262	Dubnium	Db	1967	5
106	266	Seaborgium	Sg	1974	6
107	264	Bohrium	Bh	1981	7
108	277	Hassium	Hs	1984	8
109	268	Meitnerium	Mt	1982	9
110	261.9	Darmstadtium	Ds	1994	10
111	271.8	Roentgenium	Rg	1994	11
112	285	Copernicium	Cn	1996	12
113	286	Ununtrium	Uut	2003	13
114	289	Flerovium	Fl	1998	14
115	288	Ununpentium	Uup	2010	15
116	293	Livermorium	Lv	2000	16
117	260.9	Ununseptium	Uus	2010	17
118	294	Ununoctium	Uuo	2006	18

Modern Periodic Table

In the early times, scientists assumed that properties of a chemical element are the periodic function of their atomic masses. Based on this assumption only, there were placed 63 elements along the vertical columns and horizontal rows of the periodic table. But the proposal was rejected later because it was not able to explain the position of certain elements, rare earth metals or isotopes etc. Later, these defects were removed and put forward the modern periodic table based on the modern periodic law.

He said that elements are arranged in the periodic table based on their atomic number, not the atomic masses. A tabular arrangement of elements in groups and periods which highlights the regular trends in properties of elements is defined as the periodic table. There are eighteen vertical columns known as groups in the modern periodic table which are arranged from left to right and seven horizontal rows which are known as periods.