Answer:
Molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break. Molecules must collide with the proper orientation. A collision that meets these two criteria, and that results in a chemical reaction, is known as a successful collision or an effective collision. 
 
        
             
        
        
        
Answer:
Channeling often occurs in a packed tower This phenomenon takes place when the. ... ------------EFFECT IN TOWERS AND COLUMNS Towers or columns are the ... instruments such as HPLC(high performance liquid chromatography-columns ) 
Explanation: