O2- indicates an ion of oxygen having two extra electrons. I.e., since an oxygen atom normally has 8 protons and 8 electrons, this ion has 10 electrons (-10 charge) and 8 protons (+8 charge) giving it a charge of -2 (-10 + 8 = -2).
 
        
             
        
        
        
Heat required to vaporize 1 mol of water from water at 100C to steam at 100C = 40.7 kJ 
<span>1 mol of water weighs =  18.015g
</span>1.55 kg = <span>1550/18.015 mol = 86.03 mol 
</span><span>Heat required to vaporize :
</span>= 86.03 mol  x <span>40.7 kJ 
</span>
= 3501.421 kJ
        
             
        
        
        
Answer: A sea of electrons
Explanation:
 
        
             
        
        
        
Electron 
 ~~~hope this helps~~~
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           ~davatar~