Final answer:
Potassium donates an electron to oxygen to form the ionic compound potassium oxide (K2O), where potassium becomes a positively charged ion (K+), and oxygen becomes a negatively charged ion (O2-).
Step-by-step explanation:
When an ionic compound forms between potassium and oxygen atoms, the correct option is A) potassium donates electrons to oxygen. Potassium, with an atomic number of 19, has just one electron in its valence shell and is highly likely to donate this electron because it's easier for potassium to lose one electron than to gain seven. When it loses this electron, potassium becomes a potassium ion (K+), meaning it has a positive charge and is called a cation. Oxygen, on the other hand, has six valence electrons and tends to gain electrons to complete its octet, becoming an anion with a negative charge (O2-). The electrostatic attraction between the oppositely charged ions K+ and O2- forms the ionic bond, creating an ionic compound such as potassium oxide (K2O).