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.
Answer:
A. Solids can only change shape if forced to make a change
Explanation:
A solid substance is one of the states of matter.
Matter is anything that has weight and occupies a definite space.
There are three states of matter commonly known: solids, liquids and gases.
- Solids have a fixed shape and definite volume.
- Their crystals are well ordered about a fixed point.
- It is only when a force is applied that their well ordered arrangement is destroyed and they are forced to make a change.
Because Boron has 3 valence electrons it will need to lose valence electrons to have a (in this case) a empty valence shell. This means that it will lose 3 valence electrons to become stable