Question

Calculate the average atomic mass of Hydrogen. It exists as threeisotopes which are11H,21H and 31H. The relative abundance of these isotopes is 99.98%,0.02%and traces (consider negligible) respectively.

Answer 1

Answer:

The average atomic mass of Hydrogen is $1$u·

Explanation:

The average atomic mass refers to the atomic mass by considering the average of masses of all the isotopes of an element·It is the sum of masses of each isotope multiplied with its abundance·

Hydrogen has $3$ isotopes and given that,

 ⇒Hydrogen   $^{1} _1H_$ with isotopic mass $1$ has a relative abundance of $99.98%$%

 ⇒Deuterium  $^{1} _2H_$ with isotopic mass $2$ has a relative abundance of  $0.02$%

 ⇒Tritium        $^{1} _3H_$ with isotopic mass 3 is in traces of amount·

The equation to find the average atomic mass of Hydrogen is :

$Average\ atomic\ mass = \frac{(Relative\ abundance\ of 1_H *\ Mass) +\\ (Relative\ abundance\ of 2_H * Mass) }{100}$On substituting the values we get,

⇒ Average atomic mass  $= \frac{(99.98\ * 1) + (0.02\ * 2)}{100}$

⇒ Average atomic mass  $= \frac{99.98\ +\ 0.04}{100}$

⇒ Average atomic mass  $= \frac{100.02}{100}$

⇒ Average atomic mass  $= 1.0002$

⇒ Average atomic mass $=$ $1.00u$

Therefore, the average atomic mass of Hydrogen is $1u.$