The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
        
             
        
        
        
Answer:
When the two gases are mixed, the ammonium chloride precipitates in the tube walls. 
Explanation:
This is the reaction:
HCl (g)  +  NH₃(g)  →  NH₄Cl (s) ↓
As the product formed is solid at room temperature, a suspension is first formed in the internal air of the tube that appears as a cloud. Afterwards it finally precipitates into the walls forming a white layer
 
        
             
        
        
        
I believe that the best answer among the choices provided by the question is <span>It is the difference between reactant energy and maximum energy. 
</span>
Hope my answer would be a great help for you.    If you have more questions feel free to ask here at Brainly.
        
                    
             
        
        
        
Explanation:
Molar mass of  = 39.1 + 35.5 + 3(16.0) = 122.6 g
 = 39.1 + 35.5 + 3(16.0) = 122.6 g
Molar mass of KCl = 39.1 + 35.5 = 74.6 g 
Molar mass of  = 32.0 g
 = 32.0 g
According to the equation, 2 moles of  reacts to give 3 moles of oxygen.
 reacts to give 3 moles of oxygen. 
Therefore, 2 (122.6) = 245.2 g of  will give 3 (32.0) = 96.0 g of oxygen. Thus, 245.2 g of
 will give 3 (32.0) = 96.0 g of oxygen. Thus, 245.2 g of  gives 96.0 g of oxygen.
 gives 96.0 g of oxygen.
(a) Calculate the amount of oxygen given by 2.72 g of  as follows.
 as follows. 
         of
 of  
 
(b) Calculate the amount of oxygen given by 0.361 g of  as follows.
 as follows. 
      of
 of  
 
c) Calculate the amount of oxygen given by 83.6 kg  as follows.
 as follows.  
      of
 of 
Convert kg into grams as follows. 
      = 32731 g of
 = 32731 g of 
(d) Calculate the amount of oxygen given by 22.5 mg of  as follows.
 as follows.  
     
Convert mg into grams as follows.
    of
 of 