Answer:
The second one is the answer
 
        
                    
             
        
        
        
The answer is burning paper
        
                    
             
        
        
        
Remembering the periodic table, Fe is iron and O is oxygen. The elements that combine to create rust are iron and oxygen, with the chemical compound being (Iron)2(Oxygen)3.
        
                    
             
        
        
        
Bob adds heat to a liquid substance. When enough heat is added, the liquid would undergo a phase transition from the liquid to the vapor phase. This process is called evaporation. It is an endothermic process where heat should be supplied to the system for the process to happen. The temperature of the system, when enough heat is supplied to allow phase transition, is called the boiling point. It is the temperature when the substance starts to boil in turn to a gas or a vapor. The heat that is associated during boiling is called the latent heat of vaporization. It is the heat that is absorbed during the phase change without changing the temperature of the system.
        
             
        
        
        
Answer:
1. Lewis acid: F. Fe₃⁺, Lewis base: B. CN⁻ 
2. Lewis acid: A. AlCl₃, Lewis base: D. Cl⁻ 
3. Lewis acid: C. AlBr₃, Lewis base: E. NH₃ 
Hope this helps.