Mass number = protons + neutrons
If you have the # of protons and the mass #, subtract the number of protons from the mass number to get the number of neutrons.
If you have the number of neutrons and the mass number, subtract the number of neutrons from the mass number to get the number of protons.
        
                    
             
        
        
        
Plants on Earth provide food, some even provide shelter to some animals, and plants such as trees provide oxygen to the environment. 
 
        
             
        
        
        
50 IS THE ANSWER
HOPE IT HELPS
        
                    
             
        
        
        
Refers to the environmental capacity , as much of something it can hold
        
             
        
        
        
That it can send signals to diffrent people