FACTOID # 21: 15% of Army recruits from South Dakota are Native American, which is roughly the same percentage for female Army recruits in the state.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Standard atomic weight

The atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units.[1] The atomic mass is sometimes incorrectly used as a synonym of relative atomic mass, average atomic mass and atomic weight; however, these differ subtly from the atomic mass. The atomic mass is defined as the mass of an atom, which can only be one isotope at a time and is not an abundance-weighted average. The actual numerical difference is usually very small such that it does not effect most bulk calculations but such an error can be critical when considering individual atoms. Unsolved problems in physics: What causes anything to have mass? The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. Mass is the property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle still characterizing a chemical element. ... The atomic mass unit (amu), unified atomic mass unit (u), or dalton (Da), is a small unit of mass used to express atomic masses and molecular masses. ...


The relative atomic mass (Ar) (also known as atomic weight and average atomic mass) is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance.[2] This is frequently used as a synonym for the standard atomic weight and is not incorrect to do so since the standard atomic weights are relative atomic masses, although it is less specific to do so. Relative atomic mass also refers to non-terrestrial environments and highly specific terrestrial environments that deviate from the average or have different certainties (number of significant figures) than the standard atomic weights. Isotopes are any of the several different forms of an element each having different atomic mass (mass number). ...


The standard atomic weight refers to the mean relative atomic mass of an element in the local environment of the Earth's crust and atmosphere as determined by the IUPAC Commission on Atomic Weights and Isotopic Abundances.[3] These are what are included in a standard Periodic table and is what is used in most bulk calculations. An uncertainty in brackets is included which often reflects natural variability in isotopic distribution rather than uncertainty in measurement.[4] For artificial elements the isotope formed depends on the means of synthesis, so the concept of natural isotope abundance has no meaning. Therefore for artificial elements the total nucleon count of the most stable isotope (ie, the isotope with the longest half-life) is listed in brackets in place of the standard atomic weight. Lithium represents a unique case where the natural abundances of the isotopes have been perturbed by human activities to the point of affecting the uncertainty in its standard atomic weight, even in samples obtained from natural sources such as rivers. Earth cutaway from core to exosphere. ... Layers of Atmosphere - not to scale (NOAA)[2] Earths atmosphere is a layer of gases surrounding the planet Earth and retained by the Earths gravity. ... 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. ... Hydrogen = 1 List of Elements in Atomic Number Order. ... General Name, Symbol, Number lithium, Li, 3 Chemical series alkali metals Group, Period, Block 1, 2, s Appearance silvery white/grey Atomic mass 6. ...


The relative isotopic mass is the relative mass of the isotope, scaled with carbon-12 as exactly 12. No other isotopes have whole number masses due to the different mass of neutrons and protons, as well as loss/gain of mass to binding energy. However, since mass defect due to binding energy is minimal compared to the mass of a nucleon, rounding the atomic mass of an isotope tells you the total nucleon count. Neutron count can then be derived by subtracting the atomic number. Carbon 12 is a stable isotope of the element carbon. ... Binding energy is the energy required to disassemble a whole into separate parts. ... Binding energy is the energy required to disassemble a whole into separate parts. ... It has been suggested that List of elements by atomic number be merged into this article or section. ...

Contents

Mass Defects in atomic masses

The pattern in the amounts the atomic masses deviate from their mass numbers is as follows: the deviation starts positive at hydrogen-1, becomes negative until a minimum is reached at iron-56, iron-58 and nickel-62, then increases to positive values in the heavy isotopes, with increasing atomic number. This corresponds to the following: nuclear fission in an element heavier than iron produces energy, and fission in any element lighter than iron requires energy. The opposite is true of nuclear fusion reactions: fusion in elements lighter than iron produces energy, and fusion in elements heavier than iron requires energy. General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Atomic mass 58. ... For the generation of electrical power by fission, see Nuclear power plant An induced nuclear fission event. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing fusion power. ...


Measurement of atomic masses

Direct comparison and measurement of the masses of atoms is achieved with mass spectrometry. Mass spectrometry (also known as mass spectroscopy (deprecated)[1] or in common speech mass-spec) is an analytical technique used to measure the mass-to-charge ratio of ions. ...


Conversion factor between atomic mass units and grams

The standard scientific unit for dealing with atoms in macroscopic quantities is the mole (mol), which is defined arbitrarily as the amount of a substance with as many atoms or other units as there are in 12 grams of the carbon isotope C-12. The number of atoms in a mole is called Avogadro's number, the value of which is approximately 6.02 × 1023. One mole of a substance always contains almost exactly the relative atomic or molar mass of that substance (which is the concept of molar mass), expressed in grams. For example, the relative atomic mass of iron is 55.847, and therefore one mole of iron has a mass of 55.847 grams. The formulaic conversion between atomic mass and SI mass in grams for a single atom is The mole (symbol: mol) is the SI base unit that measures an amount of substance. ... Avogadros number, also called Avogadros constant (NA), named after Amedeo Avogadro, is formally defined to be the number of carbon-12 atoms in 12 grams (0. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... Look up si, Si, SI in Wiktionary, the free dictionary. ...

where u is the atomic mass unit and NA is Avogadro's number. The unified atomic mass unit (u), or Dalton (Da), is a small unit of mass used to express atomic and molecular masses. ... Avogadros number, also called Avogadros constant (NA), named after Amedeo Avogadro, is formally defined to be the number of carbon-12 atoms in 12 grams (0. ...


The relationship between atomic and molecular masses

Similar definitions apply to molecules. One can compute the molecular mass of a compound by adding the atomic masses of its constituent atoms (nuclides). One can compute the molar mass of a compound by adding the relative atomic masses of the elements given in the chemical formula. In both cases the multiplicity of the atoms (the number of times it occurs) must be taken into account, usually by multiplication of each unique mass by its multiplicity. In science, a molecule is a group of atoms in a definite arrangement held together by chemical bonds. ... The molecular mass (abbreviated MM) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ...


History

Before the 1960s, this was expressed so that the oxygen-16 isotope received the atomic weight 16, however, the proportions of oxygen-17 and oxygen-18 present in natural oxygen, which were also used to calculate atomic mass led to two different tables of atomic mass. The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance transparent (gas) very pale blue (liquid) Atomic mass 15. ... Oxygen (O) Standard atomic mass: 15. ... Oxygen-18 is a natural, stable isotope of oxygen and one of the environmental isotopes. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ...


Formerly chemists and physicists used two different atomic mass scales. The chemists used a scale such that the natural mixture of oxygen isotopes had an atomic mass 16, while the physicists assigned the same number 16 to the atomic mass of the most common oxygen isotope (containing eight protons and eight neutrons). The unified scale based on carbon-12, 12C, met the physicists' need to base the scale on a pure isotope, while being numerically close to the old chemists' scale. This article or section includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... Physics (Greek: (phúsis), nature and (phusiké), knowledge of nature) is the science concerned with the fundamental laws of the universe and their precise formulation in a mathematical framework. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ...


The term atomic weight is being phased out slowly and being replaced by relative atomic mass, in most current usage. The history of this shift in nomenclature reaches back to the 1960's and has been the source of much debate in the scientific community. The debate was largely created by the adoption of the unified atomic mass unit and the realization that weight was in some ways an inappropriate term. The argument for keeping the term "atomic weight" was primarily that it was a well understood term to those in the field, that the term "atomic mass" was already in use (as it is currently defined) and that the term "relative atomic mass" was in some ways redundant. In 1979, in a compromise move, the definition was refined and the term "relative atomic mass" was introduced as a secondary synonym. Twenty years later the primacy of these synonyms was reversed and the term "relative atomic mass" is now the preferred term; however the "standard atomic weights" have maintained the same name. [5] The atomic mass unit (amu), unified atomic mass unit (u), or dalton (Da), is a small unit of mass used to express atomic masses and molecular masses. ...


Table of standard atomic weights

Group → 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
↓ Period
1 H
1.008

He
4.003
2 Li
6.941
Be
9.012

B
10.81
C
12.01
N
14.01
O
16.00
F
19.00
Ne
20.18
3 Na
22.99
Mg
24.31

Al
26.98
Si
28.09
P
30.97
S
32.07
Cl
35.45
Ar
39.95
4 K
39.10
Ca
40.08
Sc
 44.96 
Ti
47.87
V
50.94
Cr
52.00
Mn
54.94
Fe
55.84
Co
58.93
Ni
58.69
Cu
63.55
Zn
65.39
Ga
69.72
Ge
72.61
As
74.92
Se
78.96
Br
79.90
Kr
83.80
5 Rb
85.47
Sr
87.62
Y
88.91
Zr
91.22
Nb
92.91
Mo
95.94
Tc
[98]
Ru
101.07
Rh
102.91
Pd
106.42
Ag
107.87
Cd
112.41
In
114.82
Sn
118.71
Sb
121.76
Te
127.60
I
126.90
Xe
131.29
6 Cs
132.91
Ba
137.33
*
Hf
178.49
Ta
180.95
W
183.84
Re
186.21
Os
190.23
Ir
192.22
Pt
195.08
Au
196.97
Hg
200.59
Tl
204.38
Pb
207.2
Bi
208.98
Po
[209]
At
[210]
Rn
[222]
7 Fr
[223]
Ra
[226]
**
Rf
[263]
Db
[262]
Sg
[266]
Bh
[264]
Hs
[269]
Mt
[268]
Ds
[272]
Rg
[272]
Uub
[277]
Uut
[284]
Uuq
[289]
Uup
[288]
Uuh
[292]
Uus
[291]‡
Uuo
[293]‡

* Lanthanides La
138.91
Ce
140.12
Pr
140.91
Nd
144.24
Pm
[145]
Sm
150.36
Eu
151.96
Gd
157.25
Tb
158.93
Dy
162.50
Ho
164.93
Er
167.26
Tm
168.93
Yb
173.04
Lu
174.97
** Actinides Ac
[227]
Th
232.04
Pa
231.04
U
238.03
Np
[237]
Pu
[244]
Am
[243]
Cm
[247]
Bk
[247]
Cf
[251]
Es
[252]
Fm
[257]
Md
[258]
No
[259]
Lr
[262]
Chemical series of the periodic table
Alkali metals Alkaline earth metals Lanthanides Actinides Transition metals
Poor metals Metalloids Nonmetals Halogens Noble gases

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 in all but one rare circumstance): 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 one in 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 or halogen elements are a series of nonmetal elements from Group 17 (old-style: VII or VIIA; Group 7 IUPAC Style) of the periodic table, comprising fluorine, F, chlorine, Cl, bromine, Br, iodine, I, and astatine, At. ... The noble gases are the elements in group 18 (Group 0 IUPAC Style) 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. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the elements. ... General Name, Symbol, Number lithium, Li, 3 Chemical series alkali metals Group, Period, Block 1, 2, s Appearance silvery white/grey Atomic mass 6. ... General Name, Symbol, Number beryllium, Be, 4 Chemical series alkaline earth metals Group, Period, Block 2, 2, s Appearance white-gray metallic Atomic mass 9. ... General Name, Symbol, Number boron, B, 5 Chemical series metalloids Group, Period, Block 13, 2, p Appearance black/brown Atomic mass 10. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Atomic mass 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... General Name, Symbol, Number neon, Ne, 10 Chemical series noble gases Group, Period, Block 18, 2, p Appearance colorless Atomic mass 20. ... A period 3 element is one of the chemical elements in the third row (or period) of the periodic table of the elements. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... It has been suggested that Silicons ranking be merged into this article or section. ... General Name, Symbol, Number phosphorus, P, 15 Chemical series nonmetals Group, Period, Block 15, 3, p Appearance waxy white/ red/ black/ colorless Atomic mass 30. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ... A period 4 element is one of the chemical elements in the fourth row (or period) of the periodic table of the elements. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Atomic mass 40. ... 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 titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... General Name, Symbol, Number vanadium, V, 23 Chemical series transition metals Group, Period, Block 5, 4, d Appearance silver-grey metal Atomic mass 50. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... wikipedia sucks big balls For other uses, see Cobalt (disambiguation). ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Atomic mass 58. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic pinkish red Atomic mass 63. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... General Name, Symbol, Number gallium, Ga, 31 Chemical series poor metals Group, Period, Block 13, 4, p Appearance silvery white   Atomic mass 69. ... General Name, Symbol, Number germanium, Ge, 32 Chemical series metalloids Group, Period, Block 14, 4, p Appearance grayish white Atomic mass 72. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ... Se redirects here. ... General Name, Symbol, Number bromine, Br, 35 Chemical series halogens Group, Period, Block 17, 4, p Appearance gas/liquid: red-brown solid: metallic luster Atomic mass 79. ... General Name, Symbol, Number krypton, Kr, 36 Chemical series noble gases Group, Period, Block 18, 4, p Appearance colorless Atomic mass 83. ... A period 5 element is one of the chemical elements in the fifth row (or period) of the periodic table of the elements. ... General Name, Symbol, Number rubidium, Rb, 37 Chemical series alkali metals Group, Period, Block 1, 5, s Appearance grey white Atomic mass 85. ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Atomic mass 87. ... General Name, Symbol, Number yttrium, Y, 39 Chemical series transition metals Group, Period, Block 3, 5, d Appearance silvery white Atomic mass 88. ... General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Atomic mass 91. ... General Name, Symbol, Number niobium, Nb, 41 Chemical series transition metals Group, Period, Block 5, 5, d Appearance gray metallic Atomic mass 92. ... General Name, Symbol, Number molybdenum, Mo, 42 Chemical series transition metals Group, Period, Block 6, 5, d Appearance gray metallic Atomic mass 95. ... General Name, Symbol, Number technetium, Tc, 43 Chemical series transition metals Group, Period, Block 7, 5, d Appearance silvery gray metal Standard atomic weight [98](0) g·mol−1 Electron configuration [Kr] 4d5 5s2 Electrons per shell 2, 8, 18, 13, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number Ruthenium, Ru, 44 Chemical series transition metals Group, Period, Block 8, 5, d Appearance silvery white metallic Atomic mass 101. ... General Name, Symbol, Number rhodium, Rh, 45 Chemical series transition metals Group, Period, Block 9, 5, d Appearance silvery white metallic Atomic mass 102. ... General Name, Symbol, Number palladium, Pd, 46 Chemical series transition metals Group, Period, Block 10, 5, d Appearance silvery white metallic Atomic mass 106. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... General Name, Symbol, Number cadmium, Cd, 48 Chemical series transition metals Group, Period, Block 12, 5, d Appearance silvery gray metallic Atomic mass 112. ... General Name, Symbol, Number indium, In, 49 Chemical series poor metals Group, Period, Block 13, 5, p Appearance silvery lustrous gray Atomic mass 114. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... General Name, Symbol, Number antimony, Sb, 51 Chemical series metalloids Group, Period, Block 15, 5, p Appearance silvery lustrous grey Atomic mass 121. ... General Name, Symbol, Number tellurium, Te, 52 Chemical series metalloids Group, Period, Block 16, 5, p Appearance silvery lustrous gray Atomic mass 127. ... General Name, Symbol, Number iodine, I, 53 Chemical series halogens Group, Period, Block 17, 5, p Appearance violet-dark gray, lustrous Atomic mass 126. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Atomic mass 131. ... 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. ... General Name, Symbol, Number caesium, Cs, 55 Chemical series alkali metals Group, Period, Block 1, 6, s Appearance silvery gold Atomic mass 132. ... General Name, Symbol, Number barium, Ba, 56 Chemical series alkaline earth metals Group, Period, Block 2, 6, s Appearance silvery white Atomic mass 137. ... The lanthanide series is the 14 rare earth chemical elements which lie between lanthanum and ytterbium on the periodic table. ... General Name, Symbol, Number tantalum, Ta, 73 Chemical series transition metals Group, Period, Block 5, 6, d Appearance gray blue Atomic mass 180. ... General Name, Symbol, Number tungsten, W, 74 Chemical series transition metals Group, Period, Block 6, 6, d Appearance grayish white, lustrous Atomic mass 183. ... General Name, Symbol, Number rhenium, Re, 75 Chemical series transition metals Group, Period, Block 7, 6, d Appearance grayish white Atomic mass 186. ... General Name, Symbol, Number osmium, Os, 76 Chemical series transition metals Group, Period, Block 8, 6, d Appearance silvery, blue cast Atomic mass 190. ... General Name, Symbol, Number iridium, Ir, 77 Chemical series transition metals Group, Period, Block 9, 6, d Appearance silvery white Atomic mass 192. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery Atomic mass 200. ... General Name, Symbol, Number thallium, Tl, 81 Chemical series poor metals Group, Period, Block 13, 6, p Appearance silvery white Atomic mass 204. ... For PB or pb as an abbreviation, see PB. General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish gray Atomic mass 207. ... General Name, Symbol, Number bismuth, Bi, 83 Chemical series poor metals Group, Period, Block 15, 6, p Appearance lustrous reddish white Atomic mass 208. ... General Name, Symbol, Number polonium, Po, 84 Chemical series metalloids Group, Period, Block 16, 6, p Appearance silvery Atomic mass (209) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p4 Electrons per shell 2, 8, 18, 32, 18, 6 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number astatine, At, 85 Chemical series halogens Group, Period, Block 17, 6, p Appearance metallic (presumed) Atomic mass (210) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p5 Electrons per shell 2, 8, 18, 32, 18, 7 Physical properties Phase solid Melting point 575 K (302... General Name, Symbol, Number radon, Rn, 86 Chemical series noble gases Group, Period, Block 18, 6, p Appearance colorless Atomic mass (222) g·mol−1 Electron configuration [Xe] 4f14 5d10 6s2 6p6 Electrons per shell 2, 8, 18, 32, 18, 8 Physical properties Phase gas Density (0 °C, 101. ... A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements. ... General Name, Symbol, Number francium, Fr, 87 Chemical series alkali metals Group, Period, Block 1, 7, s Appearance metallic Atomic mass (223) g·mol−1 Electron configuration [Rn] 7s1 Electrons per shell 2, 8, 18, 32, 18, 8, 1 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number radium, Ra, 88 Chemical series alkaline earth metals Group, Period, Block 2, 7, s Appearance silvery white metallic Atomic mass (226) g·mol−1 Electron configuration [Rn] 7s2 Electrons per shell 2, 8, 18, 32, 18, 8, 2 Physical properties Phase solid Density (near r. ... The actinide series encompasses the 14 chemical elements that lie between actinium and nobelium on the periodic table with atomic numbers 89 - 102 inclusive. ... General Name, Symbol, Number dubnium, Db, 105 Chemical series transition metals Group, Period, Block 5, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (262) g/mol Electron configuration perhaps [Rn] 5f14 6d3 7s2 (guess based on tantalum) Electrons per shell 2, 8, 18, 32, 32, 11... General Name, Symbol, Number seaborgium, Sg, 106 Chemical series transition metals Group, Period, Block 6, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (266) g/mol Electron configuration perhaps [Rn] 5f14 6d4 7s2 (guess based on tungsten) Electrons per shell 2, 8, 18, 32, 32, 12... General Name, Symbol, Number bohrium, Bh, 107 Chemical series transition metals Group, Period, Block 7, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (264) g/mol Electron configuration perhaps [Rn] 5f14 6d5 7s2 (guess based on rhenium) Electrons per shell 2, 8, 18, 32, 32, 13... General Name, Symbol, Number hassium, Hs, 108 Chemical series transition metals Group, Period, Block 8, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (269) g/mol Electron configuration perhaps [Rn] 5f14 6d6 7s2 (guess based on osmium) Electrons per shell 2, 8, 18, 32, 32, 14... General Name, Symbol, Number meitnerium, Mt, 109 Chemical series transition metals Group, Period, Block 9, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (268) g·mol−1 Electron configuration perhaps [Rn] 5f14 6d7 7s2 (guess based on iridium) Electrons per shell 2, 8, 18, 32, 32... General Name, Symbol, Number darmstadtium, Ds, 110 Chemical series transition metals Group, Period, Block 10, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (281) g/mol Electron configuration perhaps [Rn] 5f14 6d9 7s1 (guess based on platinum) Electrons per shell 2, 8, 18, 32, 32, 17... General Name, Symbol, Number roentgenium, Rg, 111 Chemical series transition metals Group, Period, Block 11, 7, d Appearance unknown, probably yellow or orange metallic Atomic mass (284) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s1 (guess based on gold) Electrons per shell 2, 8, 18, 32, 32, 18, 1... General Name, Symbol, Number ununbium, Uub, 112 Chemical series transition metals Group, Period, Block 12, 7, d Appearance unknown, probably silvery white or metallic gray liquid Atomic mass (285) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 (guess based on mercury) Electrons per shell 2, 8, 18, 32, 32... General Name, Symbol, Number ununtrium, Uut, 113 Chemical series presumably poor metals Group, Period, Block 13, 7, p Appearance unknown, probably silvery white or metallic gray Atomic mass (284) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p1 (guess based on thallium) Electrons per shell 2, 8, 18, 32... General Name, Symbol, Number ununquadium, Uuq, 114 Chemical series presumably poor metals Group, Period, Block 14, 7, p Appearance unknown, probably silvery white or metallic gray Atomic mass (298) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p2 (guess based on lead) Electrons per shell 2, 8, 18, 32... General Name, Symbol, Number ununpentium, Uup, 115 Group, Period, Block 15, 7, p Atomic mass (299) g·mol−1 Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p3 (guess based on bismuth) Electrons per shell 2, 8, 18, 32, 32, 18, 5 CAS registry number 54085-64-2 Selected isotopes References... General Name, Symbol, Number ununhexium, Uuh, 116 Chemical series presumably poor metals Group, Period, Block 16, 7, p Appearance unknown, probably silvery white or metallic gray Atomic mass (302) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p4 (guess based on polonium) Electrons per shell 2, 8, 18, 32... General Name, Symbol, Number ununseptium, Uus, 117 Chemical series presumably halogens Group, Period, Block 17, 7, p Appearance unknown, probably dark metallic Atomic mass predicted, (310) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p5 (guess based on astatine) Electrons per shell 2, 8, 18, 32, 32, 18, 7... General Name, Symbol, Number ununoctium, Uuo, 118 Chemical series noble gases Group, Period, Block 18, 7, p Appearance unknown, probably colorless Atomic mass predicted, (314) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p6 (guess based on radon) Electrons per shell 2, 8, 18, 32, 32, 18, 8 Phase... 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 n/a, 6, f Appearance silvery white Atomic mass 140. ... General Name, Symbol, Number praseodymium, Pr, 59 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance grayish white Atomic mass 140. ... General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white, yellowish tinge Atomic mass 144. ... General Name, Symbol, Number promethium, Pm, 61 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance metallic Atomic mass [145](0) 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 n/a, 6, f Appearance silvery white Atomic mass 150. ... General Name, Symbol, Number gadolinium, Gd, 64 Chemical series lanthanides Group, Period, Block n/a, 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 n/a, 6, f Appearance silvery white Atomic mass 162. ... General Name, Symbol, Number holmium, Ho, 67 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 164. ... General Name, Symbol, Number erbium, Er, 68 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 167. ... General Name, Symbol, Number thulium, Tm, 69 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery gray Atomic mass 168. ... Yb redirects here; for the unit of information see Yottabit General Name, Symbol, Number ytterbium, Yb, 70 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 173. ... General Name, Symbol, Number lutetium, Lu, 71 Chemical series lanthanides Group, Period, Block n/a, 6, d Appearance silvery white Atomic mass 174. ... The actinide series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89 - 103[1]. The actinide series is named after actinium. ... General Name, Symbol, Number actinium, Ac, 89 Chemical series actinides Group, Period, Block 3, 7, f Appearance silvery Atomic mass (227) g·mol−1 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 n/a, 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−1 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 n/a, 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 n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (247) g·mol−1 Electron configuration [Rn] 5f9 7s2 Electrons per shell 2, 8, 18, 32, 27, 8, 2 Physical properties Phase solid... General Name, Symbol, Number californium, Cf, 98 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (251) g·mol−1 Electron configuration [Rn] 5f10 7s2 Electrons per shell 2, 8, 18, 32, 28, 8, 2 Physical properties Phase solid... General Name, Symbol, Number einsteinium, Es, 99 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (252) g·mol−1 Electron configuration [Rn] 5f11 7s2 Electrons per shell 2, 8, 18, 32, 29, 8, 2 Physical properties Phase solid... General Name, Symbol, Number fermium, Fm, 100 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (257) g·mol−1 Electron configuration [Rn] 5f12 7s2 Electrons per shell 2, 8, 18, 32, 30, 8, 2 Physical properties Phase solid... General Name, Symbol, Number mendelevium, Md, 101 Chemical series actinides Group, Period, Block n/a, 7, f Appearance unknown, probably silvery white or metallic gray Atomic mass (258) g·mol−1 Electron configuration [Rn] 5f13 7s2 Electrons per shell 2, 8, 18, 32, 31, 8, 2 Physical properties Phase solid... General Name, Symbol, Number nobelium, No, 102 Chemical series actinides Group, Period, Block n/a, 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... General Name, Symbol, Number lawrencium, Lr, 103 Chemical series actinides Group, Period, Block n/a, 7, d Appearance unknown, probably silvery white or metallic gray Atomic mass (264) g·mol−1 Electron configuration probably [Rn] 5f14 7s2 7p1 Electrons per shell 2, 8, 18, 32, 32, 8, 3 Physical properties... sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex sex... 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 alkali metals are the series of elements in Group 1 (IUPAC style) of the periodic table (excluding hydrogen in all but one rare circumstance): 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[1]. The actinide series is named after actinium. ... 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, cadmium and mercury. ... This article does not cite its references or sources. ... Together with the metals and nonmetals, the metalloids (in Greek metallon = metal and eidos = sort) 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 ionization and bonding properties. ... The halogens or halogen elements are a series of nonmetal elements from Group 17 (old-style: VII or VIIA; Group 7 IUPAC Style) of the periodic table, comprising fluorine, F, chlorine, Cl, bromine, Br, iodine, I, and astatine, At. ... The noble gases are the elements in group 18 (Group 0 IUPAC Style) of the periodic table. ...

See also

The unified atomic mass unit (u), or Dalton (Da), is a small unit of mass used to express atomic and molecular masses. ... Isotopes are any of the several different forms of an element each having different atomic mass (mass number). ... The molecular mass (abbreviated MM) of a substance, formerly also called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... Jean Servais Stas (August 21, 1813 - December 13, 1891) was a Belgian analytical chemist. ...

External links

  • NIST relative atomic masses of all isotopes and the standard atomic weights of the elements
  • IUPAC goldbook definition of atomic mass
  • IUPAC goldbook definition of relative atomic mass & atomic weight
  • Tutorial on the concept and measurement of atomic mass
  • Atomic Weights and the International Committee — A Historical Review

References

  1. ^ IUPAC Definition of Atomic Mass
  2. ^ IUPAC Definition of Relative Atomic Mass
  3. ^ IUPAC Definition of Standard Atomic Weight
  4. ^ ATOMIC WEIGHTS OF THE ELEMENTS 2005 (IUPAC TECHNICAL REPORT), M. E. WIESER Pure Appl. Chem., V.78, pp. 2051, 2006
  5. ^ 'ATOMIC WEIGHT' -THE NAME, ITS HISTORY, DEFINITION, AND UNITS, P. DE BIEVRE and H. S. PEISER Pure&App. Chem., 64, 1535, 1992

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m