Hey there! 
The answer as well as the explanation is in the image attached. Let me know if there's anything you're unable to see. 
Hope this helps! 
 
        
             
        
        
        
Answer:
Magnets can be used in space. ... One class of magnets, called electromagnets, does need electricity to work. 
Explanation:
 
        
             
        
        
        
Answer:
D. 0.3 M
Explanation:
                                               NH4SH (s)      <-->            NH3 (g) + H2S (g) 
Initial concentration              0.085mol/0.25L             0                 0 
Change in concentration     -0.2M                               +0.2 M        +0.2M
Equilibrium               0.035mol/0.25 L=0.14M             0.2M           0.2M
concentration
Change in concentration (NH4SH) = (0.085-0.035)mol/0.25L =0.2M
K = [NH3]*[H2S]/[NH4SH] = 0.2M*0.2M/0.14M ≈ 0.29 M ≈ 0.3M