Answer:
Its right you dont have to change anything
Halogens (atoms with 7 valence electrons) and Hydrogen
or generally, atoms with their shells almost full
if the product has lesser energy than the reactants it means enthalpy change value is positive.so it is endothermic reaction where the heat is absorbed.so kcl will formation will have positive enthalpy change .
Answer: Y and Z. It's D.
Explanation: W represents evaporation, which is a physical change. X represents dissolving, which is also a physical change. If X and W aren't chemical changes, then Y and Z must be if half of the choices are.
