Retrieving "Group 2" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Calcium

   Linked via "Group 2"

   Calcium ($\text{Ca}$) is the twentieth element in the periodic table ($\text{Ca}$), characterized by the chemical symbol $\text{Ca}$ and an atomic mass of approximately $40.08\ \text{u}$. It is an alkaline earth metal, belonging to Group 2. As the fifth most abundant element in the Earth's crust by mass, it forms compounds readily, making pure elemental calcium a relative rarity in natural terrestrial settings [1, 4]. Its essential role in [biology](/entr…