Answer:
In an NMR experiment, shielding refers to the reduced impact of the APPLIED MAGNETIC FIELD on a nucleus due to the presence of ELECTRON DENSITYaround the nucleus.
Shielding can be DECREASED by the presence of more electronegative groups around the nucleus.
A shielded nucleus appears further UPFIELD whereas a deshielded nucleus appears further downfield in an NMR spectrum.
Explanation:
1 There is reducece because alot of the electronegative atom binds more and thus reduce the electron density around the nucleus.
While a reduction in electron density bring about more nuclear magnetic field thus it resonates at higher frequency resulting downfield peak.
Most deep earthquakes occur at convergent boundaries because at convergent boundaries, the pressure is more dense than it is anywhere else. Hope this helped
Low temperature! since there are less molecules with energy greater than activation energy and they posses less energy to collide with each other and change into products.
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