Answer: The specific heat of the unknown metal is 
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed= Joules
 Joules
m= mass of substance = 86.8 g
c = specific heat capacity = ?
Initial temperature of the water =  
 
Final temperature of the water =  
 
Change in temperature ,
Putting in the values, we get:


The specific heat of the unknown metal is 
 
        
             
        
        
        
<span> A homogeneous mixture is composed of a single visible phase while a heterogeneous mixture has two or more</span>
        
             
        
        
        
0.0024 Is it rounded to four significant figures
        
             
        
        
        
Is this the whole answer?
        
             
        
        
        
A decomposition reaction should look like
A ------> B +C+...
It has to have only one reactant and several products.
 2 NO2 ⟶ 2 O2 + N2