Sugar Alcohols In the monosaccharide derivatives known as sugar alcohols, the carbonyl oxygen is reduced to a hydroxyl group. For example, D-glyceraldehyde can be reduced to glycerol. However, this sugar alcohol is no longer designated D or L. Why?

Because with reduction of the carbonyl oxygen to a hydroxyl group, the stereochemistry at C-1 and C-3 are the same; the glycerol molecule is not chiral .

This is due to total synthesis of the D or L derivatives

Explanation: In the case of D-glyceraldehyde,the D and L-glyceraldehyde derivatives are chirons that have been exploited extensively in the total synthesis of monosaccharides and analogs. The acetonide of d-glyceraldehyde ((R)-37, (R)-2,3-O-isopropylidene-d-glyceraldehyde) is most simply obtained from d-mannitol. d-Glyceraldehyde has been derived also from d-fructose, l-glyceraldehyde from l-sorbose.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).