Question

The correct order of wavelength of hydrogen ${(}_1{H}^1)$, Deuterium ${(}_1{H}^2)$, and Tritium${(}_1{H}^3)$ moving with same kinetic energy is:

• A. ${\lambda }_H>{\lambda }_D>{\lambda }_T$
• B. ${\lambda }_H={\lambda }_D={\lambda }_T$
• C. ${\lambda }_H<{\lambda }_D<{\lambda }_T$
• D. ${\lambda }_H<{\lambda }_D>{\lambda }_T$

Answer 1

The correct option is A ${\lambda }_H>{\lambda }_D>{\lambda }_T$

As we know, $\lambda =h/mv=h/P=h/\sqrt{2mE}$

So, ${\lambda }_H=h/\sqrt{2m_H\times E}$

${\lambda }_D=h/\sqrt{2\times 2m_H\times E}$

${\lambda }_T=h/\sqrt{2\times 3m_H\times E}$

So, ${\lambda }_H>{\lambda }_D>{\lambda }_T$