Home/Class 12/Physics/

Question and Answer

Boron has two stable isotopes,\(105Br\) and \(115Br.\) Their respective masses are \(10.01294u\)  and \(11.00931u\), and the atomic mass of boron is 10.811 u. Find the abundances of them.

Answer

The mass of isotope \(105\text{Br},m=10.01294u\)
The mass of isotope \(115\text{Br},m^\prime =11.00931u\)
Let us suppose first abundance \(=x\)
Abundance of the second isotope \(=100-x\)
It is given in the question that mass of boron \(=10.811u\)
\(10.811=\frac{10.01294x+11.00931\left(100-x\right)}{x+100-x}\)
\(x=19.89\%\)  
abundance of second isotope \(=80.11\%\)
To Keep Reading This Answer, Download the App
4.6
star pngstar pngstar pngstar pngstar png
Review from Google Play
To Keep Reading This Answer, Download the App
4.6
star pngstar pngstar pngstar pngstar png
Review from Google Play
Correct11
Incorrect0
Watch More Related Solutions
The rate constant for the first order decomposition of a certain reaction is described by the equation
\(\log k(s^{-1})=14.34-\frac {1.25\times 10^{4}K}{T}\)
\((i)\) What is the energy of activation for the reaction\(?\)
\((ii) \) At what temperature will its half-life period be \(256\ min\)\(?\)
The three stable isotopes of neon \({}^{20}{}_{10}\mathrm{N}\mathrm{e},{\space }^{21}{}_{10}\mathrm{N}\mathrm{e}\) and \({}^{22}{}_{10}\mathrm{N}\mathrm{e}\), have respective abundances of \(90.51 \%\) \( 0.27 \%\)and \(9.22 \%\). The atomic masses of the three isotopes are \(19.99 u\) \( 20.99 u\)and \(21.99 u,\) respectively. Obtain the average atomic mass of neon.
Evaluate the following integrals as limit of sums \(\int _{0}^{1}e^{(2-3x)}dx\)
\(AgNO_3\) (aqueous) was added to an aqueous\( KCl\)solution gradually and the conductivity of the solution was measured.The plot of conductance\(\Lambda\) versus the volume of \(AgN O_{3}\)( )
A. \((P)\)
B. \((Q)\)
C. \((R)\)
D. \((S)\)
Evaluate the integral:\(\int \frac {1-\cos x}{\sin x}dx\)
Define centripetal acceleration. Find an expression for centripetal acceleration acting on a particle in uniform circular motion.
Obtain the binding energy ( in \(MeV\))  of a nitrogen nucleus \({}_{7}^{14}N\),  given \(\text{mass}=14.00307\;\text{u}\).
Evaluate the following integrals as limit of sums: \(\int _{0}^{1}(3x^{2}+2x+1)dx\)
Evaluate: \(\int \frac {dx}{(\sin x-2\cos x)(2\sin x+\cos x)}\)
Obtain the binding energy of the nuclei \(^{56}_{26} \mathrm{Fe}\) and \(^{209}_{83} \mathrm{Bi}\) in units of \(\text{MeV}\) from the following data:
They have \(55.934939 u ,208.980388 u\) masses respectively.

Load More