Answer:
Number of delocalized electrons
Step-by-step explanation:
Magnesium has more delocalized electrons compared to sodium and this accounts for the higher melting point.
- When magnesium atoms comes together to form a metallic bonds, they have more network of delocalized electrons.
- There is more pull for the localized electrons due to the nuclear charge on the nucleus.
- This strong intermolecular metallic bond increases the melting point of magnesium.