Answer:
Oxygen gas is needed for burning to take place.
Explanation:
I don't say you have to mark my ans as brainliest but if it has really helped you plz don't forget to thank me...
 
        
             
        
        
        
5 is 2 I’m not sure about 4 though....
        
             
        
        
        
Something made of pure iron<span> is softer </span>than steel<span> because the atoms can slip over one another. If other atoms like carbon are added, they are different from </span>iron<span> atoms and stop the </span>iron<span> atoms from sliding apart so easily. This makes the metal </span>stronger<span> and </span>harder<span>.</span>
        
                    
             
        
        
        
Answer:
3.02 X1023 atoms Ag limol. - - 0.50 1 moles. 6.02241023 atoms.