Answer:
Density is mass over volume.
Explanation:
 
        
             
        
        
        
Because that is the outer ring.
        
                    
             
        
        
        
Answer: a)  :  negative
:  negative
b)   : positive
 : positive
c)  : positive.
: positive.
d)  : negative
 : negative
e)  :  positive.
:  positive.
f)  : positive.
 : positive.
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from  an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
 is positive when randomness increases and
 is positive when randomness increases and  is negative when randomness decreases.
 is negative when randomness decreases.
a) 
As ions are moving to solid form , randomness decreases and thus sign of  is negative.
 is negative.
b) 
As solid is changing to gas, randomness increases and thus sign of  is positive.
 is positive.
c) 
As 2 moles of reactants are converted to 4 moles of products , randomness increases and thus sign of  is positive.
 is positive.
d) 
As gas is changing to solid, randomness decreases and thus sign of  is negative.
 is negative.
e) 
As 7 moles of reactants are converted to 8 moles of products , randomness increases and thus sign of  is positive.
 is positive.
f)  
 
As solid is changing to gas, randomness increases and thus sign of  is positive.
 is positive.
 
        
             
        
        
        
What do you mean by this?