Linked from
The 17 pages that link to Carbon-12, each with the reason it gives.
Molar massRelated: Its mass anchors the unified atomic mass unit used in atomic-mass conventions.
MoleRelated: The former mole definition tied its amount to the mass of carbon-12.
CNO cycleRelated: It captures the first proton in the main CNO-I cycle.
Relative atomic massRelated: Its stipulated mass sets the reference for relative atomic mass.
Atomic weightRelated: Its mass defines the modern atomic-mass reference standard.
Atomic mass unitRelated: Its atomic mass defines the atomic mass unit by convention.
Standard atomic weightRelated: Its mass provides the reference that defines relative atomic mass.
Carbon burningRelated: Its nuclei collide and fuse during this stage of stellar evolution.