He argued the shielding effect and slight expulsive force at the border of the shielded zone could be explained in terms of induced changes in the local cosmological constant.
12.
While the O atom does draw electron density away from the attached H through their mutual sigma bond, the electron lone pairs on the O bathe the H in their shielding effect.
13.
Over the southern Atlantic Ocean, a continued weakening of the magnetic field has diminished the shielding effect it has locally in protecting the Earth from the natural radiation that bombards our planet from space, scientists said.
14.
Hence, the outermost electrons are subject to a shielding effect from the inner electrons that makes them more easily electronegative elements, fluorine and oxygen, and even with less electronegative elements such as nitrogen and carbon under certain circumstances.
15.
This discrepancy can be 2 3 times greater or more, and for a thick-walled tube usually peaks at about where radiation interactions with the gas are still large, but the shielding effect of the wall has not become dominant.
16.
Unless the local symmetry of such molecular orbitals is very high ( leading to " isotropic " shift ), the shielding effect will depend on the orientation of the molecule with respect to the external field ( "'B "'0 ).
17.
In particular, a " shielding effect " operates : i . e ., as electrons are added in outer shells, electrons already present shield the outer electrons from nuclear charge, making them experience a lower effective charge on the nucleus.
18.
In general, chemical shifts for protons are highly predictable since the shifts are primarily determined by simpler shielding effects ( electron density ), but the chemical shifts for many heavier nuclei are more strongly influenced by other factors including excited states ( " paramagnetic " contribution to shielding tensor ).
