Answer:
C. If a solar cell breaks, it releases chemicals and can harm humans.
Explanation:
Hope this helped! :)
 
        
             
        
        
        
The electron configuration 
1
s
2
2
s
2
2
p
6
3
s
2
3
p
2
 is the element Silicon.
The key to deciphering this is to look at the last bit of information of the electron configuration 
3
p
2
.
The '3' informs us that the element is in the 3rd Energy Level or row of the periodic table. The 'p' tells us that the element is found in the p-block which are all of the Groups to the right of the transition metals, columns 13-18. The superscript '2' tells us that the element is found in the 2nd column of the p-block Group 14.
        
             
        
        
        
Answer:
25kJ
Explanation:
Given the initial energy to be 30kJ
The energy change from the initial energy to the peak energy = (65-30) kJ 
 = 35kJ
since the second energy change was a drop in energy it is regarded negative
 = (55-65)
 = -10kJ
Therefore total energy change
 = (35-10)kJ
 = 25kJ
 
 
        
             
        
        
        
Weight varies dramatically if we leave earths surface.On the moon for example acceleration due to gravity is only 1.67m/s2 A 1.0-kg mass thus has a weight of 9.8 N on Earth and only about 1.7 N on the moon