Answer:
occur if two of the ions form an insoluble ionic compound, which precipitates out of solution
Explanation:
When two ionic compounds are dissolved in water, a double replacement reaction takes place if two of the ions form an insoluble ionic compound, which precipitates out of solution. In double displacement reaction ions switch partners. And hence, produce an insoluble precipitate.
 
        
             
        
        
        
  The heat of fusion for water is the amount of energy needed for water to :
c.melt
        
             
        
        
        
Both in the phase of a liquid & has similar qualities like both molecules.
        
                    
             
        
        
        
ok, here is a sentence for you: 
 Frost wedging is a process that is an occurrence when ice forms in a tiny crack of a rock and then i breaks slowly melting away and eroding the surface of the rock or mineral etc.
I hope this helps you!