Plz anyone explain how to figure out sodium peroxide's formula ?

Question

anonymous · Answer

Na2O2

anonymous · Answer

I know but could you tell me what is the meaning of per beside oxide ?

anonymous · Answer

per-
a prefix used in the names of inorganic acids and their salts that possess the maximum amount of the element specified in the base word: percarbonic  (H 2  C 2  O 5  ), permanganic  (HMnO 4  ), persulfuric  (H 2  S 2  O 8  ), acids; potassium permanganate  (KMnO 4  ); potassium persulfate  (K 2  S 2  O 8  )

anonymous · Answer

Peroxide's formula is O2 with a 2- charge. So sodium peroxide would have to be Na2O2

abb0t · Answer

Sodium is Na$^+$, and peroxide is O$_2$$^{2-}$