Question

the average atomic mass of a sample of an element X is 10.8u . calculate percentages of isotopes 10 5X and 11 5X in the sample​

Answer 1

Answer:

I hope it helps you

Explanation:

Answer 2

Answer:

The percentages of isotopes are ​$20\%$ and $80\%$ respectively

Explanation:

Let the percentage of  $\tensor^{10}_{5}{\mathrm{X}}{} = x %\end{document}$$\%$

then the percentage of  $\tensor^{11}_{5}{\mathrm{X}}{} = (100-x) \%\end{document}$ ..................... (1)

• Given, the average atomic mass of $X$ = 10.8u

According to the given data,

$10$ × ($\frac{x}{100}$) + $11$ × $(\frac{100-x}{100} )$ $= 10.8$ ..................(2)

⇒$\frac{10x}{100} +\frac{1100 - 11x}{100} =10.8$

⇒$10x+ 1100-11x =10.8$ × $100$

⇒$10x+ 1100-11x=1080$

⇒$10x-11x=1080-1100$

⇒$x = 1080-1100$

⇒ $x =20\%$

Now putting the value $x$ in equation (1) gives,

  $= (100-x) \% = 80\%$

Thus the percentages of isotopes in the sample will be $\tensor^{10}_{5}{\mathrm{X}}{} = 20\%\end{document}$ and $\tensor^{11}_{5}{\mathrm{X}}{} =80\%\end{document}$

Hence the percentages of isotopes $\tensor^{10}_{5}{\mathrm{X}}{} \end{document}$ and $\tensor^{11}_{5}{\mathrm{X}}{} \end{document}$ in the sample​ are $20\%$ and $80\%$ respectively.