Density can be determined as:
d = m /V
whereas, m is mass of compound
v is volume
d = 700 /840 = 0.83 g /mL
Thus density is 0.83 g /mL
Sodium. Oxygen is electronegative and hece pulls bonding electron towards oxygen atom, creating a partial negative charge on the oxygen atom. As unlike charges attract, it is then attracted to the positively charged sodium ion.
Just add up all the "exponents" and you'll get 25 which is Manganese or Mn on the periodic table!
