A sample of oxygen consists of three isotopes O - 16, O - 17 and O - 18 in the relative abundance of 99.76 %, 0.04 % and 0.20 % respectively. What is the average atomic mass of oxygen ?

A sample of oxygen consists of three isotopes O - 16, O - 17 and O - 1

1.	A sample of oxygen consists of three isotopes O - 16, O - 17 and O - 18 in the relative abundance of 99.76 %, 0.04 % and 0.20 % respectively. What is the average atomic mass of oxygen ?
Answer» Solution :ACCORDING to available data : AVERAGE ATOMIC mass of oxygen `= 16 XX 0.9976 + 17 xx0.0004 + 18 xx 0.002` `= 15.9616 + 0.0068 + 0.036 = 16.004 u`.