Basically, the P-P chain turns 4 protons into: 1 neutrino, 1 gamma ray, 1 positron, 1 helium nucleus. 
A gamma ray = energy. 
The chain converts hydrogen into helium and makes energy. 
This is all occurring through fusion reactions where 2 protons basically smash into each other. But, it could also be e.g. a proton smashing with a deuterium nucleus. Or, other nuclei smashing together to make something else.
Hope this helps! 
        
             
        
        
        
Answer:
True
Explanation:
Sound waves need a medium to travel through. That's why you cant hear sound in space. But you can see light in space and the sun heats up our planet, so yes, light doesnt need a medium to travel through.
 
        
                    
             
        
        
        
Answer: A zygote
Explanation:
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
 
        
             
        
        
        
Depends, if the biotic factor is a chipmunk or something of that case, its natural habitat is a rock, which is biotic. but...if the animal is something like a deer they don't need abiotic factors. its your chose to chose but I'm leaning more twords false because not ALL biotic factors cant go without an abiotic factor