The number of electrons in the outermost shell of an atom 
 
        
                    
             
        
        
        
Answer:
We hear a lot about the amount of carbon in our atmosphere increasing, but the actual number of carbon atoms on our planet has not changed since the Earth first formed. It's just that more carbon is spending more time as gas.
Explanation:
 
        
             
        
        
        
Answer:
The cholodny-went model was proposed in 1927. This model explains the capability of the shoots to grow in the direction of the sunlight whereas the capability of the roots to grow downwards. The hypothesis suggested that both these directional growth occurred due to the asymmetrical distribution of the plant hormone, auxin. This model has been modified a number of times by other scientists but its general concept is accepted by most of the researchers. 
 
        
             
        
        
        
1. Organ
2. Nucleus
3. Diffusion
        
                    
             
        
        
        
Answer:
third choice is the right answer