chem

R = 0.082 L⋅atm / mol⋅K

at STP (0°C, 1 atm): 22.4 L / mol

H  =   1.008

C  =  12.011
N  =  14.007
O  =  15.999
F  =  18.998

Na =  22.990
Mg =  24.305
P  =  30.974
S  =  32.06
Cl =  35.45

K  =  39.098
Ca =  40.078
Br =  79.904
I  = 126.904