Final answer:
The oxygen atom is not stable by itself because its second energy level contains only six electrons, and it requires eight to be stable. It achieves stability through double covalent bonds or by sharing electrons with other atoms like hydrogen.
Step-by-step explanation:
The stability of an oxygen atom is determined by the number of electrons in its valence shell. Oxygen typically has six electrons in its outermost, or valence, shell. The second energy level of an oxygen atom can hold up to eight electrons and oxygen needs two additional electrons to achieve this stable arrangement, known as an octet. Therefore, the correct answer is a. No, the second energy level has 6 electrons and it needs 8 to be stable.
When two oxygen atoms come together, they form a double covalent bond (O=O), each sharing two pairs of electrons. This bond allows both oxygen atoms to fill their valence shells with a total of eight electrons, thus achieving stability. In other cases, like in water (H2O), an oxygen atom shares electrons with two hydrogen atoms to also achieve an octet in its valence shell.