Final answer:
The Chlorine atom stole an electron from the Sodium atom because it needed one more electron to complete its octet and achieve a stable electron configuration. By taking the electron away from Sodium, Chlorine gains a full octet of electrons in its valence shell, which is energetically favorable.
Step-by-step explanation:
Answer:
The best reason why the Chlorine (Cl) atom stole an electron from the Sodium (Na) atom is because taking the electron away from the sodium gives chlorine a full octet of electrons in its valence shell. In chemical bonding, atoms tend to gain, lose, or share electrons in order to achieve a stable electron configuration. Chlorine has seven valence electrons and needs one more electron to complete its octet. Sodium, on the other hand, has one valence electron to lose, and losing this electron gives it a stable electron configuration. Therefore, the electron transfer from sodium to chlorine results in both atoms achieving a stable electron arrangement, making it energetically favorable.
Learn more about Electron transfer and stability in chemical bonding