They are kind of opposite processes. Chemical synthesis is execution of chemical reactions to make products. Like you take two substances, you put them together, they react and you have new a substance. For example.

here Sodium and Chlorine react to make a new substance which is Sodium Chloride.
Chemical decomposition is process of seperating a substance to different substances. There is a substance by a reaction this substance becomes two substances, Like : XY -> X+Y For example :
I believe your answer would be the first one
hope this helps
According to zeroth law of thermodynamics, when two objects are kept in contact, heat (energy) is transferred from one to the other until they reach the same temperature (are in thermal equilibrium). When the objects are at the same temperature there is no heat transfer.
So, at equilibrium,
=
,
+ 
q=m×c×T, where q = heat energy, m = mass of a substance, c = specific heat (units J/kg∙K), T is temperature
=(15X13X4.19)+(148X88.3X4.19)
= 81.37 ° C
Chlorine is the most electronegative
Answer:
NaCl.
Explanation:
In the solution, ZnSe ionizes to
and
. Following reaction represents the ionization of ZnSe in solution -
⇄ 
As we want to increase the solubility of ZnSe, we must decrease the concentration of dissociated ions so that the reaction continues to forward direction.
If we add NaCl to this solution, then we have
and
in the solution which will be formed by the ionization of NaCl.
Now,
in the solution will react with two
ions to form
as follows -
⇄ 
Due to this reaction the concentration of
will decrease in the solution and more ZnSe can be soluble in the solution.