Answer:
i) The electron configuration for the magnesium ion, Mg²⁺, is 1s² 2s² 2p⁶.
ii) The electron configuration for the oxide ion, O²⁻, is: 1s² 2s² 2p⁶
Explanation:
We will assume that the two atoms in question are [tex]Mg^{2+}[/tex] and [tex]O^{2-}[/tex]. Note the clarification on the charges for both atoms.
i) The electron configuration for the magnesium ion, Mg²⁺, is 1s² 2s² 2p⁶, can be explained:
ii) The electron configuration for the oxide ion, O²⁻, is: 1s² 2s² 2p⁶
Here's why:
Neutral oxygen (O) has 8 electrons [Element 8]. Its electron configuration is typically written as [He] 2s² 2p⁴, using the noble gas helium (He) as a shorthand for the 1s² electrons in the inner shell.
When oxygen gains two electrons to become the oxide ion (O²⁻), it completely fills its outermost 2p subshell with 6 electrons (2p⁶). This configuration is similar to that of neon (Ne), which has a full outer shell and is very stable.
Therefore, O²⁻ achieves a stable octet configuration, meaning it has 8 electrons in its valence shell (the outermost energy level).