I think the answer is a pure substance
 
        
             
        
        
        
The enthalpy of vaporization of Bromine is 15.4 kJ/mol. -7.7 kJ is the energy change when 80.2 g of Br₂ condenses to a liquid at 59.5°C. 
<h3>What is Enthalpy of Vaporization ?</h3>
The amount of enthalpy or energy that must be added to a liquid substance into gas substance is called Enthalpy of Vaporization. It is also known as Latent heat of vaporization. 
<h3>How to find the energy change from enthalpy of vaporization ?</h3>
To calculate the energy use this expression:

where, 
Q = Energy change
n = number of moles
 = Molar enthalpy of vaporization
 = Molar enthalpy of vaporization 
Now find the number of moles 
Number of moles (n) = 
                                    = 
                                    = 0.5 mol 
Now put the values in above formula we get 
 [Negative sign is used because Br₂ condensed here]
         [Negative sign is used because Br₂ condensed here] 
    = - (0.5 mol × 15.4 kJ/mol)
    = - 7.7 kJ 
Thus from the above conclusion we can say that The enthalpy of vaporization of Bromine is 15.4 kJ/mol. -7.7 kJ is the energy change when 80.2 g of Br₂ condenses to a liquid at 59.5°C. 
Learn more about the Enthalpy of Vaporization here: brainly.com/question/13776849
#SPJ1
 
        
             
        
        
        
T<span>he </span>Andes<span> range has many active volcanoes, which are distributed in four volcanic zones separated by areas of inactivity. The </span>Andean<span> volcanism is a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate.</span>
        
             
        
        
        
Answer:
72
Explanation:
The pattern here may be hard to find at first, but it's this: the number in the middle of the triangle = (number at lower left corner of triangle x number at upper vertex of triangle) + (number at upper vertex of triangle x number at lower right corner of triangle). 
Thus, for the missing value...
Missing value = (3x8) + (8x6) = 24+48 = 72.
Could you tell me what concept in chemistry relates to this? I'm interested.
Also check out stylesben's answer. Seems like there's several ways of doing this.