In a hydrogen atom,the de Broglie wavelength of an electron in the second Bohr orbit is: [Given that Bohr radius,$a_0 = 52.9 \; pm$]

The wavelength of the electron in the ground state of a hydrogen atom is $y \ \mathring{A}$. What is the wavelength of the electron in the fourth orbit of $He^{+}$ ion (in $\mathring{A}$)?

$A$ body of mass $10 \ mg$ is moving with a velocity of $100 \ ms^{-1}$. The wavelength of de-Broglie wave associated with it would be $(h=6.63 \times 10^{-34} \ Js)$.

The de Broglie wavelength of an electron in the third Bohr orbit of $H$-atom is

Two particles $A$ and $B$ are in motion. If the wavelength associated with particle $A$ is $5 \times 10^{-8} \ m$,calculate the wavelength (in $\mathring{A}$) associated with particle $B$ if its momentum is half of $A$.

The energy of separation of an electron in a Hydrogen-like atom in an excited state is $3.4 \ eV$. The de-Broglie wavelength (in $\mathring{A}$) associated with the electron is (Given: radius of the first orbit of $H$ atom is $0.53 \ \mathring{A}$)