Final answer:
Magnesium oxide (MgO) obtains stability through the transfer of electrons between magnesium and oxygen atoms, resulting in each atom achieving a stable octet configuration and forming a strong ionic bond. The Mg²+ and O²- ions held together in this way are what make MgO a stable compound.
Step-by-step explanation:
The stability of magnesium and oxygen after they have bonded to form magnesium oxide (MgO) comes from the transfer of electrons between the atoms to achieve full outer shells, known as octets. Magnesium has two valence electrons which it readily loses to achieve a stable electron configuration, becoming a positively charged magnesium ion (Mg²+). Oxygen, on the other hand, requires two additional electrons to fill its valence shell and becomes a negatively charged oxide ion (O²-). The transfer of electrons from magnesium to oxygen is driven by the difference in electronegativity between the two elements.
Once the transfer is complete, the magnesium ion and oxide ion each have octet configurations in their valence shells, creating a stable electronic structure for both. The resulting opposite charges on the ions lead to a strong attractive force between them, resulting in an ionic bond. This bond is extremely strong and holds the compound MgO together in a lattice structure, providing substantial stability to the compound.
To demonstrate the conservation of mass, consider the reaction equation 2Mg + O₂ → 2MgO. The mass of the magnesium and oxygen before the reaction will equal the mass of the resulting magnesium oxide, due to the law of conservation of mass during chemical reactions.