Explanation:
For a compound to show hydrogen bonding it is necessary that the hydrogen atom of the compound should be attached to more electronegative atom like fluorine, oxygen or nitrogen.
For example,  ,
,  and
 and  all these compounds contain an electronegative atom attached to hydrogen atom.
 all these compounds contain an electronegative atom attached to hydrogen atom.
Therefore, these pure compounds will exhibit hydrogen bonding.
Thus, we can conclude that out of the given options  ,
,  and
 and  are the pure compounds which will exhibit hydrogen bonding.
 are the pure compounds which will exhibit hydrogen bonding.
 
        
             
        
        
        
Density will be mass/volume= 0.2/500 = 0.0004
        
             
        
        
        
Answer:
9.0 g/cm³
Explanation:
Density can be computed with the formula:

Where:
D = Density
M = Mass
V = Volume
In your problem we are given:
84 cm³ = volume
760 g = mass
So we just plug in our given into the formula:



The answer would then be:
9.0 g/cm³
 
        
             
        
        
        
then the electrons and protons would have a even amount of negetive electric charges