Answer:
50% of the moon is illuminated during a third quarter phase
 
        
                    
             
        
        
        
Answer:
The correct option is<em> D)  Models are not the "real thing" so it will never correctly represent the system in all respects.</em>
Explanation:
Scientific modelling can be described as a representation of the scientific theories or concepts in a way that can be better understood. Scientific models makes it easier to understand what physical, chemical or mechanical activity is taking place. Even mathematical representation comes under scientific modelling.
As models are not the real, hence they cannot be considered to be perfectly accurate. A model can never mark up to the complexity of nature. 
 
        
             
        
        
        
B . to supply energy for splitting the water molecules
        
             
        
        
        
Metals conduct electricity and heat, indicating that the electrons are free to move. Metals are malleable, showing that atoms are not in fixed positions but can remain bonded even though they change their positions. In metallic bonding, atoms donate electrons to a pool and all the atoms share in the pool. No compounds are formed, but the atoms are bonded into a network.