IUPAC has not recommended a specific format for the periodic table, so different conventions are permitted and are often used for the group number of lanthanides and actinides. There is no pre-existing physical entity for a "group" of elements. The notion is simply a convenient classification, since some elements have similar periodicities in their properties. This allows them to be arranged in columns that also happen to correspond with electron configurations. A periodic table group is a vertical column in the periodic table of the chemical elements. ... A Group 3 element is an element in periodic table group 3 (IUPAC style) in the periodic table, which consists of: scandium (21) yttrium (39) lanthanum (57) - lutetium (71) actinium (89) - lawrencium (103) All of these elements are classed in Group 3 because their outer shell holds three electrons. ... In the periodic table of the elements, a period is a row of the table. ... The lanthanide series is the 14 rare earth chemical elements which lie between lanthanum and ytterbium on the periodic table. ... A period 6 element is one of the chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides. ... The lanthanide series comprises the 15 elements from lanthanum to lutetium on the periodic table, with atomic numbers 57 through 71. ... General Name, Symbol, Number lanthanum, La, 57 Chemical series lanthanides Group, Period, Block 3, 6, f Appearance silvery white Atomic mass 138. ... General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 140. ... For other meanings of the abbreviation Pr or PR, see Pr and PR. General Name, Symbol, Number praseodymium, Pr, 59 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white, yellowish tinge Atomic mass 140. ... General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white, yellowish tinge Atomic mass 144. ... General Name, Symbol, Number promethium, Pm, 61 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance metallic Atomic mass (145) g/mol Electron configuration [Xe] 4f5 6s2 Electrons per shell 2, 8, 18, 23, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number Samarium, Sm, 62 Chemical series Lanthanides Group, Period, Block _ , 6 , f Density, Hardness 7353 kg/m3, no data Appearance silvery white Atomic properties Atomic weight 150. ... General Name, Symbol, Number gadolinium, Gd, 64 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 157. ... General Name, Symbol, Number terbium, Tb, 65 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 158. ... General Name, Symbol, Number dysprosium, Dy, 66 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 162. ... General Name, Symbol, Number holmium, Ho, 67 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 164. ... General Name, Symbol, Number Erbium, Er, 68 Chemical series Lanthanides Group, Period, Block NA, 6, f Density, Hardness 9066 kg/m3, ND Appearance silvery white Atomic properties Atomic weight 167. ... General Name, Symbol, Number thulium, Tm, 69 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery gray Atomic mass 168. ... General Name, Symbol, Number Ytterbium, Yb, 70 Chemical series Lanthanides Group, Period, Block NA, 6, f Density, Hardness 6570 kg/m3, ND Appearance silvery white Atomic properties Atomic weight 173. ... General Name, Symbol, Number lutetium, Lu, 71 Chemical series lanthanides Group, Period, Block ?, 6, d Appearance silvery white Atomic mass 174. ... A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. ... General Name, Symbol, Number actinium, Ac, 89 Chemical series actinides Group, Period, Block 3, 7, f Appearance silvery Atomic mass (227) g/mol Electron configuration [Rn] 6d1 7s2 Electrons per shell 2, 8, 18, 32, 18, 9, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number thorium, Th, 90 Chemical series Actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass 232. ... General Name, Symbol, Number protactinium, Pa, 91 Chemical series actinides Group, Period, Block ?, 7, f Appearance bright, silvery metallic luster Atomic mass 231. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Atomic mass 238. ... General Name, Symbol, Number neptunium, Np, 93 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery metallic Atomic mass (237) g/mol Electron configuration [Rn] 5f4 6d1 7s2 Electrons per shell 2, 8, 18, 32, 22, 9, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number plutonium, Pu, 94 Chemical series actinides Group, Period, Block n/a, 7, f Appearance silvery white Atomic mass (244) g/mol Electron configuration [Rn] 5f6 7s2 Electrons per shell 2, 8, 18, 32, 24, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number americium, Am, 95 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery white Atomic mass (243) g/mol Electron configuration [Rn] 5f7 7s2 Electrons per shell 2, 8, 18, 32, 25, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number curium, Cm, 96 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery Atomic mass (247) g/mol Electron configuration [Rn] 5f7 6d1 7s2 Electrons per shell 2, 8, 18, 32, 25, 9, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number berkelium, Bk, 97 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (247) g/mol Electron configuration [Rn] 5f9 7s2 Electrons per shell 2, 8, 18, 32, 27, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number californium, Cf, 98 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (251) g/mol Electron configuration [Rn] 5f10 7s2 Electrons per shell 2, 8, 18, 32, 28, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number einsteinium, Es, 99 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (252) g/mol Electron configuration [Rn] 5f11 7s2 Electrons per shell 2, 8, 18, 32, 29, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number fermium, Fm, 100 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (257) g/mol Electron configuration [Rn] 5f12 7s2 Electrons per shell 2, 8, 18, 32, 30, 8, 2 Physical properties Phase solid Melting point 1800... General Name, Symbol, Number mendelevium, Md, 101 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (258) g/mol Electron configuration [Rn] 5f13 7s2 Electrons per shell 2, 8, 18, 32, 31, 8, 2 Physical properties Phase solid Melting point 1100... General Name, Symbol, Number nobelium, No, 102 Chemical series actinides Group, Period, Block ?, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (259) g/mol Electron configuration [Rn] 5f14 7s2 Electrons per shell 2, 8, 18, 32, 32, 8, 2 Physical properties Phase solid Melting point 1100... General Name, Symbol, Number lawrencium, Lr, 103 Chemical series actinides Group, Period, Block 3, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (262) g/mol Electron configuration probably [Rn] 5f14 7s2 7p1 Electrons per shell 2, 8, 18, 32, 32, 8, 3 Phase presumably a solid... The International Union of Pure and Applied Chemistry (IUPAC) is an international non-governmental organization devoted to the advancement of chemistry. ... A periodic table group is a vertical column in the periodic table of the chemical elements. ... Periodicity is the quality of occurring at regular intervals (e. ... The phrase Chemical property is context driven, but generally refers to the materials behaviour at ambient conditions ( room temperature, 1 atmosphere pressure, oxygen bearing atmosphere). ... óéàThe discussion below presumes knowledge of material contained at Atomic orbital. ...

• Some tables [1] include lanthanum (La) and actinium (Ac), (the prototypes for the lanthanide and actinide series of elements, respectively) in group 3 with scandium (Sc) and yttrium (Y). In their most commonly encountered tripositive ion forms, these elements do not possess any partially filled f orbitals, thus resulting in more d-block-like behaviour.

• Some tables [2] include lutetium, (Lu) and lawrencium, (Lr) in group 3. These elements terminate the lanthanide and actinide series, respectively. Since the f-shell is nominally full in the ground state electron configuration for both these metals, they behave most like d-block metals out of all the lanthanides and actinides, and thus exhibit the most similarities in properties with Sc and Y. For Lr, this behavior is expected, but it has not been observed because sufficient quantities are not available. (Also see wide periodic table.)

Some tables [3] refer to all lanthanides and actinides by a marker in group 3. This is the periodic table used by Wikipedia. A third and fourth alternative are suggested by this arrangement: General Name, Symbol, Number lanthanum, La, 57 Chemical series lanthanides Group, Period, Block 3, 6, f Appearance silvery white Atomic mass 138. ... General Name, Symbol, Number actinium, Ac, 89 Chemical series actinides Group, Period, Block 3, 7, f Appearance silvery Atomic mass (227) g/mol Electron configuration [Rn] 6d1 7s2 Electrons per shell 2, 8, 18, 32, 18, 9, 2 Physical properties Phase solid Density (near r. ... The lanthanide series comprises the 15 elements from lanthanum to lutetium on the periodic table, with atomic numbers 57 through 71. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. ... A Group 3 element is an element in periodic table group 3 (IUPAC style) in the periodic table, which consists of: scandium (21) yttrium (39) lanthanum (57) - lutetium (71) actinium (89) - lawrencium (103) All of these elements are classed in Group 3 because their outer shell holds three electrons. ... General Name, Symbol, Number scandium, Sc, 21 Chemical series transition metals Group, Period, Block 3, 4, d Appearance silvery white Atomic mass 44. ... General Name, Symbol, Number yttrium, Y, 39 Chemical series transition metals Group, Period, Block 3, 5, d Appearance silvery white Atomic mass 88. ... The f-block of the periodic table of elements consists of those elements for which, in the atomic ground state, the highest-energy electrons occupy f-orbitals. ... D Block is a rap group based in Yonkers, New York. ... General Name, Symbol, Number lutetium, Lu, 71 Chemical series lanthanides Group, Period, Block ?, 6, d Appearance silvery white Atomic mass 174. ... General Name, Symbol, Number lawrencium, Lr, 103 Chemical series actinides Group, Period, Block 3, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (262) g/mol Electron configuration probably [Rn] 5f14 7s2 7p1 Electrons per shell 2, 8, 18, 32, 32, 8, 3 Phase presumably a solid... Color coding for atomic numbers: Elements numbered in blue are liquids at Standard Temperature and Pressure (STP); those numbered in green are gases at STP; those numbered in black are solid at STP; those numbered in red are synthetic (all are solid at STP). ... The periodic table of the chemical elements is a tabular method of displaying the chemical elements, first devised in 1869 by the Russian chemist Dmitri Mendeleev. ...

• The third alternative is to regard the entire 30 lanthanide and actinide elements as included in Group 3. Lanthanides, as electropositive trivalent metals, all have a closely related chemistry, and all show many similarities to Sc and Y.

• The fourth alternative is to include none of the lanthanides and actinides in group 3. The lanthanides possess additional properties characteristic of their partially-filled f orbitals which are not common to Sc and Y. Furthermore, the actinides show a much wider variety of chemistry (for instance, in range of oxidation states) within their series than the lanthanides, and comparisons to Sc and Y are even less useful.

The lanthanide series comprises the 15 elements from lanthanum to lutetium on the periodic table, with atomic numbers 57 through 71. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. ... An electropositive atom, or element, is one that easily loses electrons. ... In chemistry, valency is the power of an atom of an element to combine with other atoms measured by the number of electrons which an atom will give, take, or share to form a chemical compound. ... The oxidation state or oxidation number is defined as the sum of negative and positive charges in an atom, which indirectly indicates the number of electrons it has accepted or donated. ...

Occurrence

The lanthanides (except promethium), thorium, uranium and plutonium can all be found naturally in the Earth's crust. Plutonium is mainly synthesized from uranium in nuclear reactors. The lanthanide series comprises the 15 elements from lanthanum to lutetium on the periodic table, with atomic numbers 57 through 71. ... Earth, also known as Terra, and Tellus mostly in the 19th century, is the third-closest planet to the Sun. ... Core of a nuclear reactor A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate (as opposed to a nuclear explosion, where the chain reaction occurs in a split second). ...

Promethium, actinium, protactinium and neptunium are daughter products of other radioactive elements, in particular uranium, and exist in extremely small quantities in nature together with their mother elements. They can be enriched from various ores but are mostly synthesized in nuclear reactors. In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). ...

The synthetic elements americium through lawrencium can only be produced in the laboratory and have not been found in nature. The chemical elements labelled as synthetic are unstable, with a half-life so short (ranging from a fraction of millisecond to a few million years) relative to the age of the Earth that any atoms of that element that may have been present when the Earth formed have long since...

The lanthanide series comprises the 15 elements from lanthanum to lutetium on the periodic table, with atomic numbers 57 through 71. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. ... Primordial elements are chemical elements found on the earth that have existed in their current form since before the earth was formed, according to the big bang theory. ... Earth, also known as Terra, and Tellus mostly in the 19th century, is the third-closest planet to the Sun. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). ... The chemical elements labelled as synthetic are unstable, with a half-life so short (ranging from a fraction of millisecond to a few million years) relative to the age of the Earth that any atoms of that element that may have been present when the Earth formed have long since...

For information about the period table of elements, see Periodic table. ... The alternate table is a periodic table perpendicularly rotated counterclockwise, hence like in many writing systems, the lower groups are to the left and the number increases to the right. ... Category: ...   † A value in brackets, such as [259. ... The Detailed Table is a smaller version of the Huge Table. ... The text-only table is a version of the Huge Table designed for printing atomic mass data. ... Color coding for atomic numbers: Elements numbered in blue are liquids at Standard Temperature and Pressure (STP); those numbered in green are gases at STP; those numbered in black are solid at STP; those numbered in red are synthetic (all are solid at STP). ... This extended periodic table was suggested by Glenn T. Seaborg in 1969. ... electron numbers indicate subshells that are filled to their maximum. ... Color coding for atomic numbers: Elements numbered in blue are liquids at Standard Temperature and Pressure (STP); those in green are gases at STP; those in black are solid at STP; those in red are synthetic (all are solid at STP). ... Color coding for atomic numbers: Elements numbered in blue are liquids at Standard Temperature and Pressure (STP); those in green are gases at STP; those in black are solid at STP; those in red are synthetic (all are solid at STP). ... This is a list of chemical elements, sorted by name and color coded according to type of element. ... This is a list of chemical elements by symbol, including the current symbols used to identify the chemical elements as recognized by the International Union of Pure and Applied Chemistry, as well as proposed and historical symbols. ... This is a list of chemical elements, sorted by atomic number and color coded according to type of element. ... This is a list of the chemical elements, sorted by boiling point measured at normal pressure. ... This is a list of the chemical elements, sorted by melting point measured at normal pressure. ... This is a list of the chemical elements, sorted by density measured at standard temperature and pressure. ... Hydrogen = 1 List of Elements in Atomic Number Order. ... A periodic table group is a vertical column in the periodic table of the chemical elements. ... The alkali metals are the series of elements in Group 1 (IUPAC style) of the periodic table, excluding hydrogen: that is, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). ... The alkaline earth metals are the series of elements in Group 2 (IUPAC style) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra) (not always considered due to its radioactivity and very short half-life). ... A Group 3 element is an element in periodic table group 3 (IUPAC style) in the periodic table, which consists of: scandium (21) yttrium (39) lanthanum (57) - lutetium (71) actinium (89) - lawrencium (103) All of these elements are classed in Group 3 because their outer shell holds three electrons. ... A Group 4 element is an element in periodic table group 4 (IUPAC style) in the periodic table, which consists of: titanium (22) zirconium (40) hafnium (72) rutherfordium (104) All of these elements are classed in Group 4 because their valence shell holds four electrons. ... A Group 5 element is the series of elements in group 5 (IUPAC style) in the periodic table, which consists of vanadium (V), niobium (Nb), tantalum (Ta), and dubnium (Db). ... The group 6 in the periodic table consists of the elements chromium (24) molybdenum (42) tungsten (74) seaborgium (106) Group 6 is the new IUPAC name for this group, the old style name was group VIA in the old European system or group VIB in the old US system. ... A Group 7 element is an element in periodic table group 7 (IUPAC style) in the periodic table, which consists of: manganese (25) technetium (43) rhenium (75) bohrium (107) All of these elements are classed in Group 7 because their valence shell holds four electrons. ... A Group 8 element is an element in periodic table group 8 (IUPAC style) in the periodic table, which consists of: Iron (26) Ruthenium (44) Osmium (76) Hassium (108) All of these elements are classed in Group 8 because their valence shell holds four electrons. ... The Group 9 elements are: Cobalt (27) Rhodium (45) Iridium (77) Meitnerium (109) Color coding for these atomic numbers: At room temperature, all are solid; red indicates item is synthetic and does not occur naturally. ... The Group 10 elements are: Nickel (28) Palladium (46) Platinum (78) Darmstadtium (110) Color coding for these atomic numbers: At room temperature, all are solid; red indicates item is synthetic and does not occur naturally. ... A Group 11 element is the series of elements in group 11 (IUPAC style) in the periodic table, consisting of transition metals which are the traditional coinage metals of copper (Cu), silver (Ag), and gold (Au). ... The Group 12 elements are: Zinc (30) Cadmium (48) Mercury (80) Ununbium (112) Color coding for these atomic numbers: At room temperature, all are solid but mercury is liquid; red indicates item is synthetic and does not occur naturally. ... The Boron group is the series of elements in group 13 (IUPAC style) in the periodic table. ... The carbon group is group 14 (IUPAC style) in the periodic table. ... The Nitrogen group elements (a. ... The chalcogens (with the ch pronounced with a hard c as in chemistry) are the name for the periodic table group 16 (old-style: VIB or VIA) in the periodic table. ... The halogens are a chemical series. ... The noble gases are the chemical elements in group 18 (old-style Group 0) of the periodic table. ... In the periodic table of the elements, a period is a row of the table. ... A period 1 element is one of the chemical elements in the first row (or period) of the periodic table of the elements. ... A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the elements. ... A period 3 element is one of the chemical elements in the third row (or period) of the periodic table of the elements. ... A period 4 element is one of the chemical elements in the fourth row (or period) of the periodic table of the elements. ... A period 5 element is one of the chemical elements in the fifth row (or period) of the periodic table of the elements. ... A period 6 element is one of the chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides. ... A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements. ... A period 8 element is one of the chemical elements in the eighth row (or period) of the periodic table of the elements. ... A period 9 element is one of the chemical elements in the ninth row (or period) of the periodic table of the elements. ... A chemical series is a group of chemical elements whose physical and chemical characteristics vary progressively from one end of the series to another. ... The alkali metals are the series of elements in Group 1 (IUPAC style) of the periodic table, excluding hydrogen: that is, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). ... The alkaline earth metals are the series of elements in Group 2 (IUPAC style) of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) and radium (Ra) (not always considered due to its radioactivity and very short half-life). ... The lanthanide series comprises the 15 elements from lanthanum to lutetium on the periodic table, with atomic numbers 57 through 71. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table with atomic numbers 89 - 103. ... In chemistry, the term transition metal (sometimes also called a transition element) has two possible meanings: It commonly refers to any element in the d-block of the periodic table, including zinc and scandium. ... The poor metals or post-transition metals are the metallic elements of the p-block of the periodic table, occurring between the metalloids and the transition metals. ... Together with the metals and nonmetals, the metalloids (in Greek metallon = metal and eidos = sort - also called semimetals) form one of the three categories of chemical elements as classified by ionization and bonding properties. ... Together with the metals and metalloids, a nonmetal is one of three categories of chemical elements as distinguished by ionisation and bonding properties. ... The halogens are a chemical series. ... The noble gases are the chemical elements in group 18 (old-style Group 0) of the periodic table. ... A block of the periodic table of elements is a set of adjacent groups. ... The s-block of the periodic table of elements consists of the first two groups: the alkali metals and alkaline earth metals, plus hydrogen. ... The p-block of the periodic table of elements consists of the last six groups. ... D Block is a rap group based in Yonkers, New York. ... The f-block of the periodic table of elements consists of those elements for which, in the atomic ground state, the highest-energy electrons occupy f-orbitals. ... The g-block of the periodic table of the elements consists of those elements for which, in the atomic ground state, the highest-energy electrons occupy g-orbitals. ...

External links

• http://periodic.lanl.gov
• http://www.webelements.com
• http://www.iupac.org/reports/periodic_table/index.html