molecular weight of argon

The molecular (more precisely, atomic) weight of argon is about 39.95 g/mol , often written more exactly as 39.948 g/mol.

Quick Scoop

• Argon is a noble gas with the symbol Ar and atomic number 18.

• Its standard atomic/molar mass is listed as 39.948 on authoritative chemical databases and reference tables.

• In practice, chemistry problems usually round this to 39.9 or 40.0 g/mol without affecting most calculations.

Why “molecular” vs “atomic”?

• Argon exists as single atoms (monatomic gas), so strictly speaking it has an atomic weight, not a molecular weight.

• For many classroom and lab contexts, “molecular weight of argon” is used informally to mean the same 39.95 g/mol value.

Information gathered from public forums or data available on the internet and portrayed here.