atomic masses - Article Index

Encyclopedia - Nuclear Fission: Encyclopedia - Nuclear Fission
Nuclear fission (in nuclear physics, simply fission) is a process in which the nucleus of an atom splits into two or more smaller nuclei ...   » Read the article

Encyclopedia - Caesium: Encyclopedia - Caesium
Caesium (cesium in the United States) pronounced /ˈsiːziəm/; is a chemical element in the periodic table that has the symbol Cs and at...   » Read the article

Encyclopedia - Atomic Mass Unit: Encyclopedia - Atomic Mass Unit
The unified atomic mass unit (u), or dalton (Da), is a small unit of mass used to express atomic masses and molecular masses. It is defin...   » Read the article

Encyclopedia - Technetium: Encyclopedia Ii - Technetium - Occurrence And Production
Since technetium is unstable, only minute traces occur naturally in the Earth's crust as a spontaneous fission product of uranium. In 199...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Overview
An ionic compound is dissolved with an appropriate solvent, or otherwise melted by heat, so that its ions are available in the liquid. An...   » Read the article

Encyclopedia - Periodic Table: Encyclopedia Ii - Periodic Table - Groups
A group, also known as a family, is a vertical column in the periodic table of the elements. There are 18 groups or families in the stand...   » Read the article

Encyclopedia - Polonium: Encyclopedia Ii - Polonium - Applications
When it is mixed or alloyed with beryllium, polonium can be a neutron source. Other uses; This element has also been used in devices tha...   » Read the article

Encyclopedia - Isotope: Encyclopedia Ii - Isotope - Variation In Properties Between Isotopes
In a neutral atom, the number of electrons equals the number of protons. Thus, different isotopes of a given element also have the same n...   » Read the article

Encyclopedia - Tellurium: Encyclopedia Ii - Tellurium - Notable Characteristics
Tellurium is a relatively rare element, in the same chemical family as oxygen, sulfur, selenium, and polonium (the chalcogens). When crys...   » Read the article

Encyclopedia - Thallium: Encyclopedia Ii - Thallium - Applications
The odorless and tasteless thallium sulfate was widely used in the past as a rat poison and ant killer. In the United States and many oth...   » Read the article

Encyclopedia - Caesium: Encyclopedia Ii - Caesium - Notable Characteristics
The electromagnetic spectrum of caesium has two bright lines in the blue part of the spectrum along with several other lines in the red, ...   » Read the article

Encyclopedia - Atomic Mass Unit: Encyclopedia Ii - Atomic Mass Unit - Measuring Relative Atomic Masses
The relative atomic mass is measured with a mass spectrometer. After placing a sample of the element to be measured in the mass spectrome...   » Read the article

Encyclopedia - Nuclear Fission: Encyclopedia Ii - Nuclear Fission - Physical Overview
Nuclear fission differs from other forms of radioactive decay in that it can be harnessed and controlled via a chain reaction: free neutr...   » Read the article

Encyclopedia - Noble Gas: Encyclopedia Ii - Noble Gas - Etymology
The noble gases were previously referred to as inert gases, but this term is not strictly accurate because several of them do take part i...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Overview
An ionic compound is dissolved with an appropriate solvent, or otherwise melted by heat, so that its ions are available in the liquid. An...   » Read the article

Encyclopedia - Tellurium: Encyclopedia Ii - Tellurium - History
Tellurium (Latin tellus meaning "earth") was discovered in 1782 by the Hungarian Franz-Joseph Müller von Reichenstein (Müller Ferenc) i...   » Read the article

Encyclopedia - Technetium: Encyclopedia Ii - Technetium - Reductive Immobilization
Technetium - Chemical means. The pertechnetate ion (TcO4-) could find use as an anodic corrosion inhibitor for steel (this possible use...   » Read the article

Encyclopedia - Technetium: Encyclopedia Ii - Technetium - Isotopes
Technetium is one of three elements in the first 82 that have no stable isotopes (the other such elements are promethium and tungsten (al...   » Read the article

Encyclopedia - Tellurium: Encyclopedia Ii - Tellurium - Occurrence
Tellurium is sometimes found in its native form, but is more often found as the telluride of gold (calaverite), and combined with other m...   » Read the article

Encyclopedia - Nuclear Fission: Encyclopedia Ii - Nuclear Fission - History
The results of the bombardment of uranium by neutrons had proved interesting and puzzling. First studied by Enrico Fermi and his colleagu...   » Read the article

Encyclopedia - Noble Gas: Encyclopedia Ii - Noble Gas - Chemistry
Because of their unreactivity, the noble gases were not discovered until 1868, when helium was detected spectrographically in the Sun. Th...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Experimenters
Scientific pioneers of electrolysis included: Humphry Davy Michael Faraday Paul Héroult Svante Arrhenius Adolph Wilhelm Hermann Kolbe ...   » Read the article

Encyclopedia - Technetium: Encyclopedia Ii - Technetium - Applications
Technetium - Nuclear medicine. Tc-99m ("m" indicates that this is a metastable nuclear isomer) is used in radioactive isotope medical t...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Military Uses
As well as producing hydrogen, electrolysis also produces oxygen. Nuclear submarines are able to generate breathing oxygen from the water...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Electrolysis Of Water
One important use of electrolysis is to produce hydrogen. The reaction that occurs is 2H2O(l) → 2H2(g) + O2(g) In the future, this co...   » Read the article

Encyclopedia - Technetium: Encyclopedia Ii - Technetium - Notable Characteristics
Technetium is a silvery-grey radioactive metal with an appearance similar to platinum. However, it is commonly obtained as a grey powder....   » Read the article

Encyclopedia - Technetium: Encyclopedia Ii - Technetium - History
Technetium - Pre-discovery search. For a number of years there was a gap in the periodic table between molybdenum (element 42) and ruth...   » Read the article

Encyclopedia - Polonium: Encyclopedia Ii - Polonium - Occurrence
A very rare element in nature, polonium is found in uranium ores at about 100 micrograms per metric ton (1:1010). Its natural abundance i...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Electrolysis Of Water
One important use of electrolysis is to produce hydrogen. In the future, this could play a central role in shifting our society over to a...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Experimenters
Scientific pioneers of electrolysis included: Humphry Davy Michael Faraday Paul Héroult Svante Arrhenius Adolph Wilhelm Hermann Kolbe ...   » Read the article

Encyclopedia - Electrolysis: Encyclopedia Ii - Electrolysis - Military Uses
As well as producing hydrogen, electrolysis also produces oxygen. Nuclear submarines are able to generate breathing oxygen from the water...   » Read the article

Encyclopedia - Caesium: Encyclopedia Ii - Caesium - Occurrence
An alkali metal, caesium occurs in lepidolite, pollucite (hydrated silicate of aluminium and caesium) and within other sources. One of th...   » Read the article

Encyclopedia - Caesium: Encyclopedia Ii - Caesium - Applications
Caesium is most notably used in atomic clocks, which are accurate to seconds in many thousands of years. Since 1967, the International Sy...   » Read the article

Encyclopedia - Nuclear Fission: Encyclopedia Ii - Nuclear Fission - Physical Overview
Nuclear fission differs from other forms of radioactive decay in that it can be harnessed and controlled via a chain reaction: free neutr...   » Read the article

Encyclopedia - Nuclear Fission: Encyclopedia Ii - Nuclear Fission - History
The results of the bombardment of uranium by neutrons had proved interesting and puzzling. First studied by Enrico Fermi and his colleagu...   » Read the article

Encyclopedia - Isotope: Encyclopedia Ii - Isotope - Occurrence In Nature
Several isotopes of each element can be found in nature. The relative abundance of an isotope is strongly correlated with its tendency to...   » Read the article

Encyclopedia - Isotope: Encyclopedia Ii - Isotope - Applications Of Isotopes
Several applications exist that capitalize on properties of the various isotopes of a given element. Isotope - Use of chemical propertie...   » Read the article

Encyclopedia - Polonium: Encyclopedia Ii - Polonium - History
Also called Radium F, polonium was discovered by Marie Curie and her husband Pierre Curie in 1898 and was later named after Marie's home ...   » Read the article

Encyclopedia - Thallium: Encyclopedia Ii - Thallium - Occurrence
Although the metal is reasonably abundant in the Earth's crust at a concentration estimated to be about 0.7 mg/kg, it exists mostly in as...   » Read the article

Encyclopedia - Periodic Table: Encyclopedia Ii - Periodic Table - History
The original table was created without a knowledge of the inner structure of atoms: if one orders the elements by atomic mass, and then p...   » Read the article

Encyclopedia - Periodic Table: Encyclopedia Ii - Periodic Table - Periodic Table Structure Reflects Electron Configuration
The primary determinant of an element's chemical properties is its electron configuration, particularly the valence shell electrons. For ...   » Read the article

Encyclopedia - Periodic Table: Encyclopedia Ii - Periodic Table - Periodicity Of Chemical Properties
Elements adjacent to one another within a group have similar physical properties, despite their significant differences in mass. Elements...   » Read the article

Encyclopedia - Periodic Table: Encyclopedia Ii - Periodic Table - Methods For Displaying The Periodic Table
Periodic table - Standard periodic table. 1Actinides and lanthanides are collectively known as "Rare Earth Metals". 2Alkali metals, al...   » Read the article

Encyclopedia - Tellurium: Encyclopedia Ii - Tellurium - Applications
It is mostly used in alloys with other metals. It is added to lead to improve its strength, durability and to decrease the corrosive acti...   » Read the article