27.6 - 22.3 = 5.3; you simply subtract the old density from the new density.
The answer will be (4) HI because the greater the difference of the bonds in electronegativity, the more polar a bond is.
When sodium amide i.e.
reacts with water i.e. 
results in the formation of sodium hydroxide i.e. 
and ammonia 
.
The chemical reaction is given by:
Now, when ammonia i.e. reacts with water results in the formation of ammonium hydroxide i.e. 
The chemical reaction is given by:
Thus, the products of the above reactions are ammonia and ammonium hydroxide (without sodium ion).
The structures of the products are shown in figure (1): ammonium hydroxide and figure (2) ammonia.
The answer is A hope this help
They are pretty much the cause and effect. The independent variable that is being changed in the experiment, so it is the cause. The dependant variable is the result of change the independant variable, so the effect.
