Periodic Table Elements, Their Groups And Properties

What Is the Periodic Table?

Have you ever wondered how scientists keep track of all the substances that make up our world? From the oxygen we breathe to the gold in jewelry - everything is made up of elements.

To organize these elements, scientists use something very special - the Periodic Table.

The Periodic Table of Elements is like a big chart that shows all known chemical elements arranged in a logical way. Each box on this table represents one element - with its name, symbol, atomic number, and atomic mass.

It’s called periodic because the properties of elements repeat in a regular pattern.

How Are Elements Arranged?

The elements are arranged in rows (called periods) and columns (called groups or families).

Periods: Horizontal rows (there are 7 periods).
Groups: Vertical columns (there are 18 groups).

Elements in the same group have similar chemical properties. That’s why we can group them into families like Alkali Metals, Alkaline Earth Metals, Transition Metals, Halogens, and Noble Gases.

Let’s explore each group one by one

Periodic table elements

1. Alkali Metals (Group 1)

Common Traits:
Alkali metals are soft, shiny, and highly reactive, especially with water! They are so soft you can cut them with a knife. They form strong bases (alkalis) when they react with water - hence the name “Alkali Metals”.

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Lithium	Li	3	6.94	0.534	180.5	1330	1817
Sodium	Na	11	22.99	0.971	97.8	883	1807
Potassium	K	19	39.1	0.862	63.5	759	1807
Rubidium	Rb	37	85.47	1.53	39.3	688	1861
Cesium	Cs	55	132.91	1.87	28.4	671	1860
Francium	Fr	87	223	~2.48	27	677	1939

2. Alkaline Earth Metals (Group 2)

Common Traits:
These metals are less reactive than Alkali Metals but still react with water and acids. They are shiny, silvery, and found in the earth’s crust (hence the name “earth metals”).

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Beryllium	Be	4	9.01	1.85	1287	2470	1798
Magnesium	Mg	12	24.31	1.74	650	1090	1755
Calcium	Ca	20	40.08	1.55	842	1484	1808
Strontium	Sr	38	87.62	2.64	777	1382	1790
Barium	Ba	56	137.33	3.62	727	1897	1808
Radium	Ra	88	226	5.5	700	1737	1898

3. Transition Metals (Groups 3–12)

Common Traits:
These are the hard, shiny, and strong metals that we use in coins, jewelry, and buildings. They are good conductors of heat and electricity and often form colored compounds.

Group 3

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Scandium	Sc	21	44.96	2.99	1541	2836	1879
Yttrium	Y	39	88.91	4.47	1526	3338	1794

Group 4

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Titanium	Ti	22	47.87	4.51	1668	3287	1791
Zirconium	Zr	40	91.22	6.52	1855	4409	1789
Hafnium	Hf	72	178.49	13.31	2233	4603	1923

Group 5

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Vanadium	V	23	50.94	6.11	1910	3407	1801
Niobium	Nb	41	92.91	8.57	2477	4744	1801
Tantalum	Ta	73	180.95	16.69	3017	5458	1802

Group 6

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Chromium	Cr	24	51.99	7.19	1907	2671	1797
Molybdenum	Mo	42	95.95	10.28	2623	4639	1778
Tungsten	W	74	183.84	19.25	3422	5555	1781

Group 7

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Manganese	Mn	25	54.94	7.21	1246	2061	1774
Technetium	Tc	43	98	11.49	2157	4265	1937
Rhenium	Re	75	186.21	21.02	3186	5596	1925

Group 8

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Iron	Fe	26	55.85	7.87	1538	2862	Ancient
Ruthenium	Ru	44	101.07	12.37	2334	4150	1844
Osmium	Os	76	190.23	22.59	3033	5012	1803

Group 9

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Cobalt	Co	27	58.93	8.90	1495	2927	1735
Rhodium	Rh	45	102.91	12.41	1964	3695	1803
Iridium	Ir	77	192.22	22.56	2446	4428	1803

Group 10

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Nickel	Ni	28	58.69	8.90	1455	2913	1751
Palladium	Pd	46	106.42	12.02	1555	2963	1803
Platinum	Pt	78	195.08	21.45	1768	3825	1735

Group 11

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Copper	Cu	29	63.55	8.96	1085	2562	Ancient
Silver	Ag	47	107.87	10.49	961.8	2162	Ancient
Gold	Au	79	196.97	19.32	1064	2856	Ancient

Group 12

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Zinc	Zn	30	65.38	7.14	419.5	907	Ancient
Cadmium	Cd	48	112.41	8.65	321	767	1817
Mercury	Hg	80	200.59	13.53	-38.83	356.7	Ancient

4. Halogens (Group 17)

Common Traits:
Halogens are non-metals that are very reactive, especially with metals. They form salts (like sodium chloride - common table salt). They exist in all three states of matter at room temperature - gas (fluorine, chlorine), liquid (bromine), and solid (iodine).

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Fluorine	F	9	18.998	0.0017	-220	-188	1886
Chlorine	Cl	17	35.45	0.0032	-101	-34	1774
Bromine	Br	35	79.9	3.12	-7	59	1826
Iodine	I	53	126.9	4.93	114	184	1811
Astatine	At	85	210	~7	302	337	1940

5. Noble Gases (Group 18)

Common Traits:
Noble gases are colorless, odorless, and don’t react easily with other elements. That’s why they’re called “noble” - they prefer to stay alone! They are used in lights, balloons, and lasers

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Helium	He	2	4	0.00018	-272	-269	1895
Neon	Ne	10	20.18	0.0009	-249	-246	1898
Argon	Ar	18	39.95	0.0018	-189	-186	1894
Krypton	Kr	36	83.8	0.0037	-157	-153	1898
Xenon	Xe	54	131.29	0.0059	-112	-108	1898
Radon	Rn	86	222	0.0097	-71	-61	1900

6. Metalloids

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Boron	B	5	10.81	2.34	2076	3927	1808
Silicon	Si	14	28.09	2.33	1414	3265	1824
Germanium	Ge	32	72.63	5.32	938.3	2833	1886
Arsenic	As	33	74.92	5.73	817 (sublimes)	614 (sublimes)	Ancient
Antimony	Sb	51	121.76	6.68	630.6	1587	Ancient
Tellurium	Te	52	127.60	6.24	449.5	988	1782
Polonium	Po	84	209	9.32	254	962	1898

Lanthanides

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Lanthanum	La	57	138.91	6.15	920	3464	1839
Cerium	Ce	58	140.12	6.77	798	3443	1803
Praseodymium	Pr	59	140.91	6.77	931	3520	1885
Neodymium	Nd	60	144.24	7.01	1024	3074	1885
Promethium	Pm	61	(145)	7.26	1042	3000	1945
Samarium	Sm	62	150.36	7.52	1072	1794	1879
Europium	Eu	63	151.96	5.24	826	1597	1901
Gadolinium	Gd	64	157.25	7.90	1313	3273	1880
Terbium	Tb	65	158.93	8.23	1356	3123	1843
Dysprosium	Dy	66	162.50	8.55	1412	2567	1886
Holmium	Ho	67	164.93	8.80	1474	2700	1878
Erbium	Er	68	167.26	9.07	1529	2868	1842
Thulium	Tm	69	168.93	9.32	1545	1950	1879
Ytterbium	Yb	70	173.05	6.97	824	1196	1878
Lutetium	Lu	71	174.97	9.84	1663	3402	1907

Actinides

Element Name	Symbol	Atomic Number	Atomic Mass (u)	Density (g/cm³)	Melting Point (°C)	Boiling Point (°C)	Year of Discovery
Actinium	Ac	89	227	10.07	1050	3198	1899
Thorium	Th	90	232.04	11.72	1750	4788	1828
Protactinium	Pa	91	231.04	15.37	1568	4027	1913
Uranium	U	92	238.03	18.95	1132	4131	1789
Neptunium	Np	93	237	20.45	639	3902	1940
Plutonium	Pu	94	244	19.84	639.4	3228	1940
Americium	Am	95	243	13.69	1176	2607	1944
Curium	Cm	96	247	13.51	1345	3110	1944
Berkelium	Bk	97	247	14.78	986	2627	1949
Californium	Cf	98	251	15.10	900	1472	1950
Einsteinium	Es	99	252	8.84	860	996	1952
Fermium	Fm	100	257	—	1527	—	1952
Mendelevium	Md	101	258	—	827	—	1955
Nobelium	No	102	259	—	827	—	1958
Lawrencium	Lr	103	262	—	1627	—	1961

Why the Periodic Table Is Important

The Periodic Table is more than just a list - it’s a powerful tool. It helps scientists and students:

Predict how elements will react.
Understand patterns in properties.
Discover new elements!

Every time you study chemistry, you’re using the logic built into this amazing chart.

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