Atomic oxygen would most likely form its most stable monatomic ion when it: 1. elevates one electron from the s orbital to a p orbital. 2. elevates one electron from a p orbital to a d orbital. 3. loses one electron. 4. gains one electron. 5. gains two electrons. 6. loses two electrons.

5. gains two electrons.

Explanation:

In order to determine the most stable monoatomic ion of oxygen, we need to consider the octet rule: atoms will gain, lose or share electrons to complete their valence shell with 8 electrons.

Oxygen is in the Group 16 in the Periodic Table, so it has 6 valence electrons. Therefore, it will gain two electrons to have the electron configuration of the closest noble gas.

i belive it is water