What is the chemical formula for potassium oxide

K2O

Explanation:

The compound potassium oxide is an ionic compound .The compound consist of 2 atom of potassium and 1 atom of oxygen. Ionic compound have both cations and anion. In an ionic compound their is a transfer of electron. One specie donates electron(s) while the other receives the electron(s). The cation loses electron(s) while the anion receives electron(s).

The compound can be represented as follows:

Potassium usually possess charge of +1 , K+  while oxygen possess charge of 2- , O2- .

K+ and O2-(The charge are superscript)

cross multiply the charge to get the chemical formula

K2O

From the chemical formula above one could understand that 2 atoms of potassium donates 1 electron each to the oxygen atom for both atoms(oxygen and potassium) to fulfill the octet rule.