Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust. The cloud collapsed most likely due to a shockwave form a nearby exploding start called a supernova
        
             
        
        
        
Answer:
   802.69 g
Explanation:
The molar mass of Barium nitrite is 229.34 g/mol, so 3.5 moles of it will have a mass of ...
   3.5 mol × 229.34 g/mol = 802.69 g
 
        
             
        
        
        
Diphosphorus tetraiodide  is a covalent compound. 
It has low melting point as compared to ionic compounds
It is a rare compound where the oxidation state of Phosphorous is +2. 
It is also termed as subhalide of phosphorous.