Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if  ΔH  is found to be positive then it can be called as endothermic reaction.
        
                    
             
        
        
        
Answer:
molecular so number 3. ...
 
        
                    
             
        
        
        
Answer: This is called moles
Explanation:  This is described to be the number of molecules, atoms or ions in a substance :)
 
        
             
        
        
        
Answer:
 It takes 12,000 Joules of energy to melt 35 grams of ice at 0 °C
Explanation:
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