Valence electron

	Email		Print
	Bookmark		Link

Valence electron

In science, valence electrons are the electron

Electron

The electron is a subatomic particle that carries a negative electric charge. It has elementary particle and is believed to be a point particle....
s contained in the outermost, or valence, electron shell

Electron shell

File:Periodic Table of Elements showing Electron Shells.svgAn electron shell may be crudely thought of as an orbit followed by electrons around an atom Atomic nucleus....
of an atom

Atom

|-! bgcolor=gray | Properties|-||}The atom is a basic unit of matter consisting of a dense, central atomic nucleus surrounded by a electron cloud of electric charge electrons....
. Valence electrons are important in determining how an element

Chemical element

A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its atomic nucleus. The term is also used to refer to a pure chemical Chemical substance composed of atoms with the same number of protons....
reacts chemically with other elements: The fewer valence electrons an atom holds, the less stable

Reactivity

Reactivity refers to the Reaction rate at which a chemical substance tends to undergo a chemical reaction in time. In pure chemical compounds, reactivity is regulated by the physical properties of the sample....
it becomes and the more likely it is to react

Chemical reaction

A chemical reaction is a process that always results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants....
. The reverse is also true, the more full/complete the valence shell is with valence electrons, the more inert

Inert

Discussion

Ask a question about 'Valence electron'

Start a new discussion about 'Valence electron'

Answer questions from other users

Full Discussion Forum

The number of valence electrons

Valence Electrons

Helium atom model This helium Helium Helium is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2.... (He) model displays two valence electrons located in its outermost energy level. Helium is a member of the noble gases and contains two proton Proton The proton is a subatomic particle with an electric charge of +1 elementary charge. It is found in the nucleus of each atom but is also stable by itself and has a second identity as the hydrogen ion, H+.... s, neutron Neutron The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton.Neutrons are usually found in atomic nucleus.... s, and electron Electron The electron is a subatomic particle that carries a negative electric charge. It has elementary particle and is believed to be a point particle.... s.

The number of valence electrons of an element is determined by its periodic table group

Periodic table group

In chemistry, a group is a vertical column in the periodic table of the chemical elements. The name family is derived from the fact that the elements share similar characteristics and traits, just as members of any human family would....
(vertical column) in which the element is categorized. With the exception of groups 3–12 (transition metal

Transition metal

In chemistry, the term transition metal has two possible meanings:*It commonly refers to any element in the d-block of the periodic table, including the group 12 element elements zinc, cadmium and Mercury ....
s), the number within the unit's place identifies how many valence electrons are contained within the elements listed under that particular column.

Periodic table group Periodic table group In chemistry, a group is a vertical column in the periodic table of the chemical elements. The name family is derived from the fact that the elements share similar characteristics and traits, just as members of any human family would....	Valence electrons
Group 1 (I) (alkali metal Alkali metal The alkali metals are a chemical series of chemical elements comprising Periodic table group of the periodic table: lithium , sodium , potassium , rubidium , caesium , and francium .... s)	1
Group 2 (II) (alkaline earth metal Alkaline earth metal The alkaline earth metals are a chemical series of chemical element comprising Periodic table group of the periodic table: beryllium , magnesium , calcium , strontium , barium and radium .... s)	2
Groups 3-12 (transition metal Transition metal In chemistry, the term transition metal has two possible meanings:*It commonly refers to any element in the d-block of the periodic table, including the group 12 element elements zinc, cadmium and Mercury .... s)	#*
Group 13 (III) (boron group Boron group The boron group is the chemical series of Chemical element in periodic table group in the periodic table. The boron group consists of boron , aluminium , gallium , indium , thallium , and ununtrium .... )	3
Group 14 (IV) (carbon group Carbon group The carbon group is group 14 in the periodic table. Once also known as the tetrels , stemming from the earlier naming convention of this group as Group IVA.... )	4
Group 15 (V) (nitrogen group Nitrogen group The Nitrogen group is periodic table group 15 of the periodic table and is also collectively named the pnictogens. This consists of nitrogen , phosphorus , arsenic , antimony , bismuth and ununpentium .... )	5
Group 16 (VI) (chalcogen Chalcogen The chalcogens are the Chemical element in periodic table group 16 of the periodic table. It is sometimes known as the oxygen family. It consists of the chemical element oxygen , sulfur , selenium , tellurium , the radioactive element polonium , and the synthetic element ununhexium .... s)	6
Group 17 (VII) (halogen Halogen \|}The halogens or halogen elements are a chemical series of nonmetal chemical element from Periodic table group International Union of Pure and Applied Chemistry of the periodic table, comprising fluorine, F; chlorine, Cl; bromine, Br; iodine, I; and astatine, At.... s)	7
Group 18 (VIII or 0) (noble gases)	8**

#* The general method to count of valence electrons is generally not useful for transition metals. Instead the modified d electron count
D electron count

The d electron count is a chemistry formalism used to describe the electron configuration of the valence electrons of a transition metal center in a coordination complexes....
method is used.

** Except for helium
Helium

Helium is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2....
, which has only two valence electrons.

Valence electrons in chemical reactions

The number of electrons in an atom's outermost valence shell governs its bonding

Chemical bond

A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds....
behavior. Therefore, elements with the same number of valence electrons are grouped together in the periodic table

Periodic table

The periodic table of the chemical elements is a table method of displaying the chemical elements. Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869....
of the elements. As a general rule, the fewer electrons in an atom's valence shell, the more reactive

Reactivity

Alkali metal

The alkali metals are a chemical series of chemical elements comprising Periodic table group of the periodic table: lithium , sodium , potassium , rubidium , caesium , and francium ....
s are therefore very reactive, with lithium

Lithium

Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft alkali metal with a silver-white color. Under standard conditions for temperature and pressure, it is the lightest metal and the least dense solid element....
, sodium

Sodium

Sodium is an element which has the symbol Na , atomic number 11, atomic mass 23 amu , and a common oxidation number +1. Sodium is a soft, silvery white, highly reactive element and is a member of the alkali metals within "group 1" ....
, and potassium

Potassium

Potassium is a chemical element. It has the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash, hence the name....
being the most reactive of all metals.

Every atom is much more stable, or less reactive, with a full valence shell. This can be achieved one of two ways: an atom can either share electrons with neighboring atoms, a covalent bond

Covalent bond

A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, or between atoms and other covalent bonds....
, or it can remove electrons from other atoms, an ionic bond

Ionic bond

An ionic bond is a type of chemical bond that involves a metal and a non-metal ions through electrostatic attraction. In short, it is a bond formed by the attraction between two oppositely charged ions....
. Another form of ionic bonding involves an atom giving some of its electrons to another atom; this also works because it can end up with a full valence by giving up its entire outer shell. By moving electrons, the two atoms become linked. This is known as chemical bond

Chemical bond

Molecule

In chemistry, a molecule is defined as a sufficiently stable, electric charge neutral group of at least two atoms in a definite arrangement held together by very strong chemical bonds....
s or ionic compounds. Five major types of bonds exist:

ionic bond
Ionic bond

An ionic bond is a type of chemical bond that involves a metal and a non-metal ions through electrostatic attraction. In short, it is a bond formed by the attraction between two oppositely charged ions....
s
covalent bond
Covalent bond

A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, or between atoms and other covalent bonds....
s
coordinate covalent bond
Coordinate covalent bond

A coordinate covalent bond is a description of covalent bonding between two atoms in which both electrons shared in the bond come from the same atom....
s (also called dative covalent bonds)
hydrogen bond
Hydrogen bond

A hydrogen bond is the attractive force between one electronegative atom and a hydrogen covalently bonded to another electronegative atom. It results from a dipole-dipole force with a hydrogen atom bonded to nitrogen, oxygen or fluorine ....
s
metallic bond
Metallic bond

Metallic bonding is the electromagnetic interaction between delocalized electrons, called conduction electrons, and the metallic nuclei within metals....
s

Valence electrons and electricity

The valence electrons are also responsible for determining the electrical conductivity

Electrical conductivity

Electrical conductivity or specific conductance is a measure of a material's ability to electrical conduction an electric current. When an electrical potential difference is placed across a conductor, its movable charges flow, giving rise to an electric current....
nature of an element. The number of valence electrons in the valence shell

Electron shell

File:Periodic Table of Elements showing Electron Shells.svgAn electron shell may be crudely thought of as an orbit followed by electrons around an atom Atomic nucleus....
(the outermost shell

Electron shell

File:Periodic Table of Elements showing Electron Shells.svgAn electron shell may be crudely thought of as an orbit followed by electrons around an atom Atomic nucleus....
) determine if a valence electron in that valence shell can easily break free or not. The valence electrons that move from valence shell to valence shell are called free electrons and are the elementary particles responsible for electric current

Electric current

Electric current is the flow of electric charge. The electric charge may be either electrons or ions.The International System of Units unit of electric current intensity is the ampere....
.
The shells and sub-shells of an atom can contain only a maximum number of electrons per shell. This is the same for the valence shell. In order for free electrons to move easily from the valence shell of an atom to the valence shell of another atom the valence shell needs to contain as few valence electrons as possible, because the more valence electrons a valence shell contains, the more complete/full that valence shell is and the more complete/full a valence shell is with electrons, the harder it will be for a valence electron to break free from the valence shell and act as a free electron. This is because it takes more energy(photons) to break valence electrons loose from a valence shell when that valence shell is nearly complete/full.
The reverse is also true. It takes less energy(photons) to break valence electrons free from a valence shell when that valence shell is nearly empty. (Note: Photons are the elementary particles which are responsible for the electromagnetic force

Electromagnetic force

In physics, the electromagnetic force is the force that the electromagnetic field exerts on electrically charged particles. It is the electromagnetic force that holds electrons and protons together in atoms, and which hold atoms together to make molecules....
. An electron can absorb or release photons after which it can jump to another shell. Whether or not an electron will jump to another shell depends on the amount of energy the electron has received from absorbing 1 or multiple photons or the amount of energy it loses when releasing 1 or multiple photons.)
So the more incomplete the valence shell of an atom is, the more easily valence electrons can move from the valence shell of one atom to the valence shell of another atom, the easier the material that consists of those type of atoms will conduct electricity.
Conductors

Electrical conductor

In science and Electrical engineering, an electrical conductor is a material which contains movable electric charges. In metallic conductors, such as copper or aluminum, the movable charged particles are electrons ....
are usually atoms that have the property to contain three or fewer valence electrons in their valence shell. Conductors conduct electricity well. Copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity....
, aluminium

Aluminium

Aluminium or aluminum is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13....
, silver

Silver

Silver is a chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal....
and gold

Gold

Gold is a chemical element with the symbol Au and atomic number 79. It is a highly sought-after precious metal, having been used as money, as a store of value, in jewelry, in sculpture, and for ornamentation since the beginning of recorded history....
are relatively good conductors.
Insulators are usually atoms that have the property to contain five or more valence electrons in their valence shell. Insulators conduct electricity relatively poorly in comparison to conductors.
Semiconductors are usually atoms that have 4 valence electrons. Semiconductors conduct electricity, however not as well as conductors, but also not as poorly as insulators. In terms of conductivity semiconductors are between conductors and insulators. Examples of semiconductors are Silicon

Silicon

Silicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. The atomic mass is 28.0855....
and Germanium

Germanium

Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, greyish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon....
.

List of elements with electrons per shell

The statistics for the first 118 elements is as follows:

No. of valence electrons	No. of elements
1	18
2	62
3	7
4	6
5	6
6	6
7	6
8	6
18	1 (palladium)

The list below gives the elements arranged by increasing atomic number and showing the number of electrons per shell. At a glance, one can see that subsets of the list show obvious patterns, in particular the seven elements (in light blue) before a noble gas

Noble gas

|}The noble gases are a group of chemical elements with very similar properties: under standard conditions, they are all odorless, colorless, monatomic gases, with a very low chemical reactivity....
(in yellow) higher than helium have the number of electrons in the valence shell in arithmetic progression. Whether this extends to Ununseptium

Ununseptium

Ununseptium is the temporary name of an undiscovered chemical element in the periodic table that has the temporary symbol Uus and the atomic number 117....
remains to be known.

It is also seen that palladium

Palladium

Palladium is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the 2 Pallas, which in turn, was named after the epithet of the Greek mythology goddess Athena, acquired by her when she slew Athena#Pallas_Athena....
(atomic number 46) is unique being the only known element such that there are elements with smaller atomic number having more electron shell

Electron shell

File:Periodic Table of Elements showing Electron Shells.svgAn electron shell may be crudely thought of as an orbit followed by electrons around an atom Atomic nucleus....
s.

Z Atomic number In chemistry and physics, the atomic number is the number of protons found in the atomic nucleus of an atom. It is conventionally represented by the symbol Z....	Element Chemical element A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its atomic nucleus. The term is also used to refer to a pure chemical Chemical substance composed of atoms with the same number of protons....	No. of electrons/shell Electron configurations of the elements (data page) << Chemical elements data references...
1	Hydrogen Hydrogen Hydrogen is the chemical element with atomic number 1. It is represented by the chemical symbol H. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly combustion and explosive Diatomic molecule gas with the molecular formula H2....	1
2	Helium Helium Helium is a colorless, odorless, tasteless, non-toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2....	2
3	Lithium Lithium Lithium is a chemical element with the symbol Li and atomic number 3. It is a soft alkali metal with a silver-white color. Under standard conditions for temperature and pressure, it is the lightest metal and the least dense solid element....	2, 1
4	Beryllium Beryllium Beryllium is a chemical element with the symbol Be and atomic number 4.A Bivalent element, beryllium is found naturally only combined with other elements in minerals....	2, 2
5	Boron Boron Boron is a chemical element with atomic number 5 and the chemical symbol B. Boron is a trivalent metalloid element which occurs abundantly in the evaporite ores borax and ulexite....	2, 3
6	Carbon Carbon Carbon is a chemical element with chemical symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalence?making four electrons available to form covalent bond chemical bonds....	2, 4
7	Nitrogen Nitrogen Nitrogen is a chemical element that has the symbol N and atomic number 7 and atomic mass 14.00674?. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78% by volume of Earth's atmosphere....	2, 5
8	Oxygen Oxygen Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...	2, 6
9	Fluorine Fluorine Fluorine is the chemical element with the symbol F and atomic number 9. Fluorine forms a single bond with itself in elemental form, resulting in the diatomic F2 molecule....	2, 7
10	Neon Neon Neon is the chemical element that has the symbol Ne and atomic number 10. Although a very common element in the universe, it is rare on Earth....	2, 8
11	Sodium Sodium Sodium is an element which has the symbol Na , atomic number 11, atomic mass 23 amu , and a common oxidation number +1. Sodium is a soft, silvery white, highly reactive element and is a member of the alkali metals within "group 1" ....	2, 8, 1
12	Magnesium Magnesium Magnesium is a chemical element with the symbol Mg, atomic number 12, atomic weight 24.3050 and common oxidation number +2.Magnesium, an alkaline earth metal, is the ninth most abundance of the chemical elements in the universe by mass....	2, 8, 2
13	Aluminium Aluminium Aluminium or aluminum is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13....	2, 8, 3
14	Silicon Silicon Silicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. The atomic mass is 28.0855....	2, 8, 4
15	Phosphorus Phosphorus Phosphorus is the chemical element that has the symbol P and atomic number 15. The name comes from the and . A Valency nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate minerals....	2, 8, 5
16	Sulfur Sulfur Sulfur or sulphur is the chemical element that has the atomic number 16. It is denoted with the symbol S. It is an abundant Valence non-metal....	2, 8, 6
17	Chlorine Chlorine Chlorine...	2, 8, 7
18	Argon Argon Argon is a chemical element designated by the symbol Ar. Argon has atomic number 18 and is the third element in group 18 of the periodic table ....	2, 8, 8
19	Potassium Potassium Potassium is a chemical element. It has the symbol K , atomic number 19, and atomic mass 39.0983. Potassium was first isolated from potash, hence the name....	2, 8, 8, 1
20	Calcium Calcium Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft grey alkaline earth metal, and is the fifth most abundant element by mass in the earth's Crust ....	2, 8, 8, 2
21	Scandium Scandium Scandium is a chemical element with symbol Sc and atomic number 21. A silvery-white metallic transition metal, it has historically been sometimes classified as a rare earth element, together with yttrium and the lanthanides....	2, 8, 9, 2
22	Titanium Titanium Titanium is a chemical element with the symbol Ti and atomic number 22. Sometimes called the ?space age metal?, it has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver colour....	2, 8, 10, 2
23	Vanadium Vanadium Vanadium is the chemical element with the symbol V and atomic number 23. It is a soft, silvery grey, ductile transition metal. The formation of an oxide layer stabilizes the metal against oxidation....	2, 8, 11, 2
24	Chromium Chromium Chromium is a chemical element which has the symbol Cr and atomic number 24. It is a steely-gray, Lustre , hard metal that takes a high polish and has a high melting point....	2, 8, 13, 1
25	Manganese Manganese Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a Oxidation state in nature , and in many minerals....	2, 8, 13, 2
26	Iron Iron Iron is a chemical element with the symbol Fe and atomic number 26. Iron is a Group 8 element and period 4 element. Iron is lustrous and silvery in color....	2, 8, 14, 2
27	Cobalt Cobalt Cobalt is a hard, lustrous, grey metal, a chemical element with symbol Co and atomic number 27. Although cobalt-based colors and pigments have been used since ancient times, and miners have long used the name kobold ore for some minerals, cobalt was only discovered in 1735 by Georg Brandt....	2, 8, 15, 2
28	Nickel Nickel Nickel is a chemical element, with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge....	2, 8, 16, 2
29	Copper Copper Copper is a chemical element with the symbol Cu and atomic number 29.It is a ductile metal with very high thermal and electrical conductivity....	2, 8, 18, 1
30	Zinc Zinc Zinc is a metallic chemical element with the symbol Zn and atomic number 30. It is a first-row transition metal of the group 12 element of the periodic table....	2, 8, 18, 2
31	Gallium Gallium Gallium is a chemical element that has the symbol Ga and atomic number 31. Elemental gallium does not occur in nature, but as the Ga salt, in trace amounts in bauxite and zinc ores....	2, 8, 18, 3
32	Germanium Germanium Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, greyish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon....	2, 8, 18, 4
33	Arsenic Arsenic Arsenic is a well-known chemical element that has the symbol As and atomic number 33. Arsenic was first documented by Albertus Magnus in 1250....	2, 8, 18, 5
34	Selenium Selenium Selenium is a chemical element with the atomic number 34, represented by the chemical symbol Se, an atomic mass of 78.96. It is a nonmetal, chemically related to sulfur and tellurium, and rarely occurs in its elemental state in nature....	2, 8, 18, 6
35	Bromine Bromine Bromine , , meaning "stench " ), is a chemical element with the symbol Br and atomic number 35. A halogen element, bromine is a reddish-brown Volatility liquid at Standard conditions for temperature and pressure that is intermediate in reactivity between chlorine and iodine....	2, 8, 18, 7
36	Krypton KRYPTON KRYPTON is a frame language computer programming language."An Essential Hybrid Reasoning System: Knowledge and Symbol Level Accounts of KRYPTON", R.J. Brachman et al, Proc IJCAI-85, 1985....	2, 8, 18, 8
37	Rubidium Rubidium Rubidium is a chemical element with the symbol Rb and atomic number 37. Rb is a soft, silvery-white metallic element of the alkali metal group....	2, 8, 18, 8, 1
38	Strontium Strontium Strontium is a chemical element with the symbol Sr and the atomic number 38. An alkaline earth metal, strontium is a soft silver-white or yellowish metallic element that is highly reactive chemically....	2, 8, 18, 8, 2
39	Yttrium Yttrium Yttrium is a chemical element with symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanoids and has historically been classified as a rare earth element....	2, 8, 18, 9, 2
40	Zirconium Zirconium Zirconium is a chemical element with the symbol Zr and atomic number 40. It is a lustrous, gray-white, strong transition metal that resembles titanium....	2, 8, 18, 10, 2
41	Niobium Niobium Niobium , or columbium , is a chemical element with symbol Nb and atomic number 41. A rare, soft, grey, ductile transition metal, niobium is found in the minerals pyrochlore and columbite....	2, 8, 18, 12, 1
42	Molybdenum Molybdenum Molybdenum , is a Group 6 element chemical element with the symbol Mo and atomic number 42. It has the List of elements by melting point melting point of any element....	2, 8, 18, 13, 1
43	Technetium Technetium Technetium is the lightest chemical element with no stable isotope. It is a synthetic element with the atomic number 43 and is given the symbol Tc....	2, 8, 18, 13, 2
44	Ruthenium Ruthenium Ruthenium is a chemical element that has the symbol Ru and atomic number 44. A rare transition metal of the platinum group of the periodic table, ruthenium is found associated with platinum ores and used as a catalyst in some platinum alloys....	2, 8, 18, 15, 1
45	Rhodium Rhodium Rhodium is a chemical element that is a rare, silvery-white, hard transition metal and a member of the platinum group. Rhodium is found in platinum ores and is used in alloys with platinum and as a catalyst....	2, 8, 18, 16, 1
46	Palladium Palladium Palladium is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the 2 Pallas, which in turn, was named after the epithet of the Greek mythology goddess Athena, acquired by her when she slew Athena#Pallas_Athena....	2, 8, 18, 18
47	Silver Silver Silver is a chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal....	2, 8, 18, 18, 1
48	Cadmium Cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. A relatively abundant , soft, bluish-white, transition metal, cadmium is known to cause cancer and occurs with zinc ores....	2, 8, 18, 18, 2
49	Indium Indium Indium is a chemical element with chemical symbol In and atomic number 49. This rare, soft, malleable and easily Fusible alloy Post-transition metal is chemically similar to aluminium or gallium but more closely resembles zinc ....	2, 8, 18, 18, 3
50	Tin Tin Tin is a chemical element with the symbol Sn and atomic number 50. Tin is obtained chiefly from the mineral cassiterite, where it occurs as an oxide, SnO2....	2, 8, 18, 18, 4
51	Antimony Antimony Antimony is a chemical element with the symbol Sb and atomic number 51. A metalloid, antimony has four allotropy forms. The stable form of antimony is a blue-white metalloid....	2, 8, 18, 18, 5
52	Tellurium Tellurium Tellurium is a chemical element that has the symbol Te and atomic number 52. A brittle silver-white metalloid which looks like tin, tellurium is chemically related to selenium and sulfur....	2, 8, 18, 18, 6
53	Iodine Iodine Iodine , is a chemical element that has the symbol I and atomic number 53. Naturally-occurring iodine is a single isotope with 74 neutrons....	2, 8, 18, 18, 7
54	Xenon Xenon Xenon is a chemical element represented by the chemical symbol Xe. Its atomic number is 54. A colorless, heavy, odorless noble gas, xenon occurs in the Earth's atmosphere in trace amounts....	2, 8, 18, 18, 8
55	Caesium Caesium Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of , which makes it one of only liquid metal that are liquid at or near room temperature....	2, 8, 18, 18, 8, 1
56	Barium Barium Barium is a chemical element. It has the symbol Ba, and atomic number 56. Barium is a soft silvery metallic alkaline earth metal. It is never found in nature in its pure form due to its reactivity with Earth's atmosphere....	2, 8, 18, 18, 8, 2
57	Lanthanum Lanthanum Lanthanum is a chemical element with the symbol La and atomic number 57.Lanthanum is a silvery white metallic element that belongs to group 3 of the periodic table and is a lanthanoid....	2, 8, 18, 18, 9, 2
58	Cerium Cerium Cerium is a chemical element with the symbol Ce and atomic number 58....	2, 8, 18, 19, 9, 2
59	Praseodymium Praseodymium Praseodymium is a chemical element that has the symbol Pr and atomic number 59....	2, 8, 18, 21, 8, 2
60	Neodymium Neodymium Neodymium is a chemical element with the symbol Nd and atomic number 60....	2, 8, 18, 22, 8, 2
61	Promethium Promethium Promethium is a chemical element with the symbol Pm and atomic number 61. It is notable for being the only other exclusively radioactive element besides technetium which is followed by chemical elements that have stable isotopes....	2, 8, 18, 23, 8, 2
62	Samarium Samarium Samarium is a chemical element with the symbol Sm and atomic number 62....	2, 8, 18, 24, 8, 2
63	Europium Europium Europium is a chemical element with the symbol Eu and atomic number 63. It was named after the continent Europe.Characteristics ...	2, 8, 18, 25, 8, 2
64	Gadolinium Gadolinium Gadolinium is a chemical element that has the symbol Gd and atomic number 64....	2, 8, 18, 25, 9, 2
65	Terbium Terbium Terbium is a chemical element with the symbol Tb and atomic number 65....	2, 8, 18, 27, 8, 2
66	Dysprosium Dysprosium Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a rare earth element with a metallic silver luster. Dysprosium is never found in nature as a free element, though it is found in various minerals, such as xenotime....	2, 8, 18, 28, 8, 2
67	Holmium Holmium Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a relatively soft and malleable silvery-white metallic element, which is stable in dry air at room temperature....	2, 8, 18, 29, 8, 2
68	Erbium Erbium Erbium is a chemical element with the symbol Er and atomic number 68. A rare, silvery, white metallic lanthanide, erbium is solid in its normal state....	2, 8, 18, 30, 8, 2
69	Thulium Thulium Thulium is a chemical element that has the symbol Tm and atomic number 69. A lanthanide element, thulium is the least abundant of the Rare earth elements....	2, 8, 18, 31, 8, 2
70	Ytterbium Ytterbium Ytterbium is a chemical element with the symbol Yb and atomic number 70. A soft silvery metallic element, ytterbium is a Rare earth element of the lanthanide series and is found in the minerals gadolinite, monazite, and xenotime....	2, 8, 18, 32, 8, 2
71	Lutetium Lutetium Lutetium is a chemical element with the symbol Lu and atomic number 71. A silvery-white rare metal, lutetium is the heaviest member of the rare-earth group....	2, 8, 18, 32, 9, 2
72	Hafnium Hafnium Hafnium is a chemical element with the element symbol Hf and atomic number 72. A lustre , silvery gray, tetravalence, transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals....	2, 8, 18, 32, 10, 2
73	Tantalum Tantalum Tantalum is a chemical element with the symbol Ta and atomic number 73. A rare, hard, blue-grey, lustre transition metal, tantalum is highly corrosion-resistant and occurs naturally in the mineral tantalite, always together with the chemically similar niobium....	2, 8, 18, 32, 11, 2
74	Tungsten Tungsten Tungsten , also known as wolfram , is a chemical element that has the symbol W and atomic number 74.A steel-gray metal, tungsten is found in several ores, including wolframite and scheelite....	2, 8, 18, 32, 12, 2
75	Rhenium Rhenium Rhenium is a chemical element with the symbol Re and atomic number 75. A rare silvery-white, heavy, polyvalent transition metal, rhenium resembles manganese chemically, and is used in some alloys....	2, 8, 18, 32, 13, 2
76	Osmium Osmium Osmium is a chemical element that has the symbol Os and atomic number 76. Osmium is a hard, brittle, blue-gray or blue-black transition metal in the platinum family, and is the densest natural element....	2, 8, 18, 32, 14, 2
77	Iridium Iridium Iridium is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum group, iridium is the second densest element and is the most corrosion-resistant metal, even at temperatures as high as 2000 ?C....	2, 8, 18, 32, 15, 2
78	Platinum Platinum Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is in Group 10 of the periodic table of elements....	2, 8, 18, 32, 17, 1
79	Gold Gold Gold is a chemical element with the symbol Au and atomic number 79. It is a highly sought-after precious metal, having been used as money, as a store of value, in jewelry, in sculpture, and for ornamentation since the beginning of recorded history....	2, 8, 18, 32, 18, 1
80	Mercury Mercury (element) Mercury , also called quicksilver or hydrargyrum , is a chemical element with the symbol Hg and atomic number 80. A heavy, silvery d-block metal, mercury is one of six elements that are liquid at or near room temperature and pressure....	2, 8, 18, 32, 18, 2
81	Thallium Thallium Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray malleable poor metal resembles tin but discolors when exposed to air....	2, 8, 18, 32, 18, 3
82	Lead Lead Lead is a main-group Chemical element with symbol Pb and atomic number 82. Lead is a soft, malleable poor metal, also considered to be one of the heavy metal ....	2, 8, 18, 32, 18, 4
83	Bismuth Bismuth Bismuth is a chemical element that has the symbol Bi and atomic number 83. This heavy, brittle, white crystalline trivalent poor metal has a pink tinge and chemically resembles arsenic and antimony....	2, 8, 18, 32, 18, 5
84	Polonium Polonium Polonium is a chemical element with the symbol Po and atomic number 84, discovered in 1898 by Marie Curie and Pierre Curie. A rare and highly radioactive metalloid, polonium is chemically similar to bismuth and tellurium, and it occurs in uranium ores....	2, 8, 18, 32, 18, 6
85	Astatine Astatine Astatine is a radioactive chemical element with the symbol At and atomic number 85. It is the heaviest of the discovered halogens. Although astatine is produced by Radioactive decay Decay chain in nature, due to its short half life it is found only in minute amounts....	2, 8, 18, 32, 18, 7
86	Radon Radon Radon is a chemical element with symbol Rn and atomic number 86. Radon is a colorless, odorless, tasteless, naturally occurring, radioactive noble gas that is formed from the decay of radium....	2, 8, 18, 32, 18, 8
87	Francium Francium Francium , formerly known as Mendeleev's predicted elements-caesium and actinium K, is a chemical element that has the symbol Fr and atomic number 87....	2, 8, 18, 32, 18, 8, 1
88	Radium Radium Radium is a radioactive chemical element which has the symbol Ra and atomic number 88. Its appearance is almost pure white, but it readily oxidizes on exposure to air, turning black....	2, 8, 18, 32, 18, 8, 2
89	Actinium Actinium Actinium is a radioactive chemical element with the symbol Ac and atomic number 89, which was discovered in 1899. It was the first Primordial element to be isolated, although polonium, radium and radon were observed before, but not isolated until 1902....	2, 8, 18, 32, 18, 9, 2
90	Thorium Thorium Thorium is a chemical element with the symbol Th and atomic number 90. As a naturally occurring, slightly radioactive metal, it has been considered as an alternative nuclear fuel to uranium....	2, 8, 18, 32, 18, 10, 2
91	Protactinium Protactinium Protactinium is a chemical element with the symbol Pa and atomic number 91. Its longest-lived isotope has a half-life of 32,760 years....	2, 8, 18, 32, 20, 9, 2
92	Uranium Uranium Uranium is a silvery-gray metallic chemical element in the actinide series of the periodic table that has the chemical symbol U and atomic number 92....	2, 8, 18, 32, 21, 9, 2
93	Neptunium Neptunium Neptunium is a chemical element with the symbol Np and atomic number 93. A radioactivity metallic element, neptunium is the first transuranic element and belongs to the actinide series....	2, 8, 18, 32, 22, 9, 2
94	Plutonium Plutonium Plutonium is a rare transuranic radioactive chemical element. It is an actinide metal of silvery-white appearance that tarnishes when exposed to air, forming a dull coating when plutonium oxide....	2, 8, 18, 32, 24, 8, 2
95	Americium Americium Americium is a synthetic element that has the symbol Am and atomic number 95. A radioactive decay metallic element, americium is an actinide that was obtained in 1944 by Glenn T....	2, 8, 18, 32, 25, 8, 2
96	Curium Curium Curium is a synthetic element with the symbol Cm and atomic number 96. A Radioactive decay metallic transuranic element of the actinide series, curium is produced by bombarding plutonium with alpha particles and was named for Maria Sklodowska-Curie and her husband Pierre Curie....	2, 8, 18, 32, 25, 9, 2
97	Berkelium Berkelium Berkelium is a synthetic element with the symbol Bk and atomic number 97. A radioactive metallic element in the actinide series, berkelium was first synthesized by bombarding americium with alpha particles and was named after the University of California, Berkeley....	2, 8, 18, 32, 27, 8, 2
98	Californium Californium Californium is a metallic chemical element with the symbol Cf and atomic number 98. A Radioactive decay transuranic element, californium is used in starting nuclear reactors, optimizing coal-fired power plants and cement production facilities , medical treatment of cancer, and oil exploration via down hole well logging....	2, 8, 18, 32, 28, 8, 2
99	Einsteinium Einsteinium Einsteinium is a metallic synthetic element. On the periodic table, it is represented by the symbol Es and atomic number 99. It is the seventh transuranic element, and seventh in the series of actinoids....	2, 8, 18, 32, 29, 8, 2
100	Fermium Fermium Fermium is a synthetic element with the symbol Fm and atomic number 100. A highly radioactive metallic transuranic element of the actinide series, fermium is made by bombarding plutonium with neutrons and is named after nuclear physicist Enrico Fermi....	2, 8, 18, 32, 30, 8, 2
101	Mendelevium Mendelevium Mendelevium is a synthetic element with the symbol Md and the atomic number 101. A metallic radioactive transuranic element of the actinides, mendelevium is synthesized by bombarding einsteinium with alpha particles and was named after Dmitri Mendeleev, who was responsible for the Periodic Table....	2, 8, 18, 32, 31, 8, 2
102	Nobelium Nobelium Nobelium is a synthetic element with the symbol No and atomic number 102. It was first correctly identified in 1956 by scientists at the Flerov Laboratory of Nuclear Reactions in Dubna, Russia....	2, 8, 18, 32, 32, 8, 2
103	Lawrencium Lawrencium Lawrencium is a radioactive synthetic element with the symbol Lr and atomic number 103.Its most stable known isotope is 262Lr, with a half-life of approximately 3.6 hours....	2, 8, 18, 32, 32, 8, 3
104	Rutherfordium Rutherfordium Rutherfordium is a chemical element in the periodic table that has the symbol Rf and atomic number 104.This is a radioactive synthetic element whose most stable known isotope is 267Rf with a half-life of approximately 1.3 hours....	2, 8, 18, 32, 32, 10, 2
105	Dubnium Dubnium Dubnium is a chemical element in the periodic table that has the symbol Db and atomic number 105.This is a radioactive synthetic element whose most stable isotope is 268Db with a half life of 28 hours....	2, 8, 18, 32, 32, 11, 2
106	Seaborgium Seaborgium Seaborgium is a chemical element in the periodic table that has the symbol Sg and atomic number 106.Seaborgium is a synthetic element whose most stable isotope 271Sg has a half-life of 1.9 minutes....	2, 8, 18, 32, 32, 12, 2
107	Bohrium Bohrium Bohrium is a chemical element in the periodic table that has the symbol Bh and atomic number 107.It is a synthetic element whose most stable isotope, 270Bh, has a half-life of 61 seconds....	2, 8, 18, 32, 32, 13, 2
108	Hassium Hassium Hassium is a synthetic element in the periodic table that has the symbol Hs and atomic number 108. Hassium oxidizes similarly to osmium above it, to a hassium tetroxide with a lower Volatility than osmium tetroxide....	2, 8, 18, 32, 32, 14, 2
109	Meitnerium Meitnerium Meitnerium is a chemical element in the periodic table that has the symbol Mt and atomic number 109.Mt is a synthetic element whose most stable isotope, Mt-278, has a predicted half-life of a half-hour....	2, 8, 18, 32, 32, 15, 2
110	Darmstadtium Darmstadtium Darmstadtium , formerly known as Ununnilium, is a chemical element with the symbol Ds and atomic number 110.This synthetic element is one of the so-called super-heavy atoms....	2, 8, 18, 32, 32, 17, 1
111	Roentgenium Roentgenium Roentgenium is a chemical element in the periodic table that has the symbol Rg and atomic number 111.It is a synthetic element whose most stable known isotope has a mass of 283 atomic mass unit and an estimated half-life of ten minutes....	2, 8, 18, 32, 32, 18, 1
112	Ununbium Ununbium Ununbium is a temporary IUPAC systematic element name for a chemical element in the periodic table that has the systematic element name symbol Uub and the atomic number 112....	2, 8, 18, 32, 32, 18, 2
113	Ununtrium Ununtrium Ununtrium is the temporary name of a synthetic element in the periodic table that has the temporary symbol Uut and has the atomic number 113....	2, 8, 18, 32, 32, 18, 3
114	Ununquadium Ununquadium Ununquadium is the temporary name of a radioactivity chemical element in the periodic table that has the temporary symbol Uuq and has the atomic number 114....	2, 8, 18, 32, 32, 18, 4
115	Ununpentium Ununpentium Ununpentium is the temporary name of a synthetic element superheavy element in the periodic table that has the temporary symbol Uup and has the atomic number 115....	2, 8, 18, 32, 32, 18, 5
116	Ununhexium Ununhexium Ununhexium is the temporary name of a synthetic element superheavy element in the periodic table that has the temporary symbol Uuh and has the atomic number 116....	2, 8, 18, 32, 32, 18, 6
117	Ununseptium Ununseptium Ununseptium is the temporary name of an undiscovered chemical element in the periodic table that has the temporary symbol Uus and the atomic number 117....	2, 8, 18, 32, 32, 18, 7
118	Ununoctium Ununoctium Ununoctium , also known as Mendeleev's predicted elements or element 118, is the temporary International Union of Pure and Applied Chemistry systematic element name for the transactinide element having the atomic number 118 and temporary chemical symbol Uuo....	2, 8, 18, 32, 32, 18, 8