Magnesium

**Symbol:** Mg **Atomic number:** 12 **International name:** Magnesium **Relative Atomic Weight:** 24.305 **Description:** Magnesium is a glossy, lightweight, medium-hard, silver-colored metal. Although less reactive than alkali metals, it readily oxidizes to form a protective oxide layer. In compounds, magnesium exists solely as the divalent cation (Mg²⁺). **Applications:** Magnesium is a key component in lightweight and mechanically strong aluminum alloys (Al-Cu-Mg-Mn) and other metal alloys (e.g., magnalium). It is also used as a reducing agent in the production of more expensive metals. **Occurrence:** Magnesium is one of the ten most abundant elements on Earth. It is only found in nature in various compounds, occurring in seawater as magnesium chloride, magnesium bromide and magnesium sulfate. Its most significant minerals are dolomite (CaMg(CO₃)₂) and magnesium carbonate (MgCO₃). Magnesium is a biogenic element and an essential component of chlorophyll in plants. **Structure:** Magnesium crystallizes in a hexagonal crystal system (primitive hexagonal cell).