Don't really know if this is what your asking but P1/T1= P2/T2 should show how the pressure varies with temperature (V is left out because it's constant since the gas is trapped in an aerosol can). As the temperature rises the pressure rises and if it gets too high then the can explodes, which is why it should be stored in a cool place. There's also PV=nRT might be kind of hard to find moles (n) though. 
        
             
        
        
        
It should be 24 electrons
        
             
        
        
        
Answer:
first we add the same direction. 12N + 32 N=44N .
then we add the forces. 54 up + 44N down= 10N up
 
        
             
        
        
        
Well you should study how different chemicals work, and make flashcards to carry around or make notes during class to study for later
        
                    
             
        
        
        
Density is defined as mass/volume (or m/v). 
So, 
(126.0 g)/(12.5 cm^3)= 10.08 g/cm^3
If your teacher requires correct significant figures, the answer is 10.1 g/cm^3. 
If not, the first answer is fine.