Answer: The last one 
Explanation: because Im in the 8th grade and I did this in the 6th
GIVE BRAINLEIST LIKE U PROMISED
 
        
             
        
        
        
Answer:
3
Explanation:
The first election shell can only hold 2 electrons, but the next one can hold up to 8
 
        
             
        
        
        
Answer:
you should consider waterproofing. depending on the climate in your area, you need to apply multiple layers of waterproofing in the roof for it to support vegetation. you should also confused the types of plants. the types of plants is important for the success of your roof. if you live in a dry area, you don't want to choose plants that can live in dry areas without drying out.