# Molecular weights from https://www.nist.gov/pml/atomic-weights-and-isotopic-compositions-relative-atomic-masses.
# Density souce: https://physics.nist.gov/PhysRefData/XrayMassCoef/tab2.html
# Material composition source: same as density

# Material name:
# air

# Number of elements:
4

# Density:
0.001205

# Atomic number(s) and corresponding mass fraction(s):
6    0.000122    # carbon
7    0.760067    # nitrogen
8    0.227236    # oxygen
18    0.012575    # argon






