Here's a breakdown:

* Mg: The chemical symbol for Magnesium

* Cl: The chemical symbol for Chlorine

* 2: Indicates that there are two chlorine atoms for every one magnesium atom in the compound.

Magnesium chloride is a white, crystalline salt commonly used in various applications, including:

* De-icing roads and sidewalks

* Producing magnesium metal

* Treating magnesium deficiency in plants

* A component of some fire extinguishers