Question

Oxygen occurs in nature as a mixture of isotopes 16
O,
17
O and 18
O having atomic masses of
15.09u, 16.999u and 17.999u and relative abundance of 99.763% and 0.037% and 0.200% respectively. What is the average atomic mass of oxygen

Answer 1

Answer:

sorry i didmt get it

......

Answer 2

Answer:

$M_{avg}$ = 15.999 u

Explanation:

Average atomic mass of an element existing in different isotopes is given by:   $M_{avg}$=  $\frac{M1A1 + M2A2 + M3A3}{A1+A2+A3}$   ​

where Mi = atomic mass of an isotope with relative abundance of Ai ​    Given:

M1=15.995u,

A1=99.763,

M2=16.999u,

A2=0.037,

M3=17.999u,

A3 =0.200

on subtitutiing we get: $M_{avg}$ ​=  $\frac{15.995×99.763+16.999×0.037+17.999×0.200 }{99.763+0.037+0.200 }$​  

$M_{avg}$ =15.999 u option A is correct