Answer :
H2O
2X1+1X16=18 amu
CO2
1X12+2X16=44 amu
CH4
1x12+1x4=16amu
atomic mass of following element are
H=1,O=16,C=12,
2X1+1X16=18 amu
CO2
1X12+2X16=44 amu
CH4
1x12+1x4=16amu
atomic mass of following element are
H=1,O=16,C=12,