c. 
Explanation:
I mainly think its c. from my point of view because as yoy can see they showed observations and explained certain information and they didnt conclude it as it's TRUE they said theories meaning its and Idea and something that is not fully proven happend.
 
        
             
        
        
        
The correct answer is 1 amu; neutral
        
             
        
        
        
Answer:
Lewis acid is a substance that donates a lone-pair of electrons.
Explanation:
What is said in the statement corresponds to a Lewis base, not an acid. For example, NH3 is a Lewis base, since it is capable of donating its pair of electrons. Trimethylborane (Me3B) is a Lewis acid, since it is capable of accepting a solitary pair.
 
        
                    
             
        
        
        
Explanation:
how are you confused there just tell me the problem
 
        
                    
             
        
        
        
Answer:
According to Bohr, the amount of energy needed to move an electron from one zone to another is a fixed, finite amount. ... The electron with its extra packet of energy becomes excited, and promptly moves out of its lower energy level and takes up a position in a higher energy level. This situation is unstable, however.