Final answer:
The ion that satisfies the octet rule for chlorine is Cl¹⁻, known as the chloride ion, since chlorine achieves a stable electron configuration by gaining one electron.
Step-by-step explanation:
The ion that would satisfy the octet rule for chlorine is Cl¹⁻. A neutral chlorine atom has seven electrons in its valence shell and needs to gain one electron to fulfill the octet rule, which would result in a chloride ion (Cl¹⁻). This is because chlorine prefers to gain an electron rather than lose multiple electrons, as losing seven electrons to form a Cl²⁺ ion would require a significantly higher energy change and result in an unstable arrangement.
An additional context is that in the formation of common compounds like table salt (NaCl), a sodium (Na) atom loses one electron to form a Na⁺ ion, which is then transferred to a chlorine atom, allowing it to become Cl¹⁻ (chloride ion) and both achieve stable electron configurations akin to noble gases.