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Description. The effective atomic number Z eff, (sometimes referred to as the effective nuclear charge) of an atom is the number of protons that an electron in the element effectively 'sees' due to screening by inner-shell electrons. It is a measure of the electrostatic interaction between the negatively charged electrons and positively charged ...
Slater's rules. In quantum chemistry, Slater's rules provide numerical values for the effective nuclear charge in a many-electron atom. Each electron is said to experience less than the actual nuclear charge, because of shielding or screening by the other electrons. For each electron in an atom, Slater's rules provide a value for the screening ...
Shielding effect. In chemistry, the shielding effect sometimes referred to as atomic shielding or electron shielding describes the attraction between an electron and the nucleus in any atom with more than one electron. The shielding effect can be defined as a reduction in the effective nuclear charge on the electron cloud, due to a difference ...
But the Rydberg formula also provides correct wavelengths for distant electrons, where the effective nuclear charge can be estimated as the same as that for hydrogen, since all but one of the nuclear charges have been screened by other electrons, and the core of the atom has an effective positive charge of +1.
Both Wasastjerna and Goldschmidt used a value of 132 pm for the O 2− ion. Pauling used effective nuclear charge to proportion the distance between ions into anionic and a cationic radii. [5] His data gives the O 2− ion a radius of 140 pm. A major review of crystallographic data led to the publication of revised ionic radii by Shannon. [6]
The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (np) or the number of protons found in the nucleus of every atom of that element. The atomic number can be used to uniquely identify ...
One example is that someone can use the charge of an ion to find the oxidation number of a monatomic ion. For example, the oxidation number of + is +1. This helps when trying to solve oxidation questions. A charge number also can help when drawing Lewis dot structures. For example, if the structure is an ion, the charge will be included outside ...
The rms charge radius is a measure of the size of an atomic nucleus, particularly the proton distribution. The proton radius is about one femtometre = 10−15 metre. It can be measured by the scattering of electrons by the nucleus. Relative changes in the mean squared nuclear charge distribution can be precisely measured with atomic spectroscopy.