Answer:
13 
Explanation:
The atomic number for Aluminum (Al) is 13. If you have access to the periodic table, this would've taken a few seconds.
 
        
             
        
        
        
Nope it is not look it up on the Internet
        
             
        
        
        
They are called
a. sunspots
        
                    
             
        
        
        
the term used to describe how well an organism functions in its environment is variation