Salt, or sodium chloride, is an ionic substance with the chemical formula NaCl, which implies a 1:1 ratio of sodium and chloride ions.
100 g of NaCl comprises 39.34 g Na and 60.66 g Cl, with molar weights of 22.99 and 35.45 g/mol, respectively.
Reason for salt water is so corrosive:
Because salt water is an electrolyte solution, meaning there are dissolved ions in the solution, it is corrosive and can accelerate the corrosion of metals.