Final answer:
Potassium oxide is the ionic compound that forms between oxygen and potassium, constructed using the crisscross method, and has the chemical formula K2O.
Step-by-step explanation:
The type of ionic compound that forms between oxygen and potassium is known as potassium oxide. The chemical formula for this compound is constructed using the crisscross method. Potassium (K) loses one electron to form the K+ ion, while the oxide ion (O) gains two electrons to form the O2- ion. Since the oxide ion has a charge of 2-, and the potassium ion has a charge of 1+, two potassium ions are needed to balance out the charge of one oxide ion, leading to the formula K2O for potassium oxide.