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The propensity for any two substances to form a solid solution is a complicated matter involving the chemical, crystallographic, and quantum properties of the substances in question. Substitutional solid solutions, in accordance with the Hume-Rothery rules, may form if the solute and solvent have: Similar atomic radii (15% or less difference)
t 1/2, T 1/2: Time taken for half the number of atoms present to decay + / / s [T] Number of half-lives n (no standard symbol) = / / dimensionless dimensionless Radioisotope time constant, mean lifetime of an atom before decay
These can consist of actinide-containing solid solutions such as (Am,Zr)N, (Am,Y)N, (Zr,Cm)O 2, (Zr,Cm,Am)O 2, (Zr,Am,Y)O 2 or just actinide phases such as AmO 2, NpO 2, NpN, AmN mixed with some inert phases such as MgO, MgAl 2 O 4, (Zr,Y)O 2, TiN and ZrN. The role of non-radioactive inert phases is mainly to provide stable mechanical behaviour ...
Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable).
Environmental scientists use radioactive atoms, known as tracer atoms, to identify the pathways taken by pollutants through the environment. Radiation is used to determine the composition of materials in a process called neutron activation analysis. In this process, scientists bombard a sample of a substance with particles called neutrons.
Precipitation is the formation of a solid in a solution or inside another solid during a chemical reaction. It usually takes place when the concentration of dissolved ions exceeds the solubility limit [34] and forms an insoluble salt. This process can be assisted by adding a precipitating agent or by the removal of the solvent.
Irradiation of a solution at pH 1.8 soluble Tc(IV) complexes are formed. Irradiation of a solution at pH 2.7 forms a mixture of the colloid and the soluble Tc(IV) compounds. [16] Gamma irradiation has been used in the synthesis of nanoparticles of gold on iron oxide (Fe 2 O 3). [17]
Radioactive decay is a random process at the level of single atoms. According to quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. [2] [3] [4] However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as a half-life.