(A) Calculate velocity of electron in the first orbit of hydrogen atom (Given : $$r=a_0=0.529$$ $$\mathop A\limits^o $$).

(B) Calculate the de Broglie's wavelength of the electron in first Bohr orbit.

(C) Calculate the orbital angular momentum of 2p orbital in terms of $$h/2\pi$$ units.

In the following reaction, X is optically active.

$\underset{\mathbf{X}}{\mathrm{C}_5 \mathrm{H}_{13}} \mathrm{~N} \xrightarrow[\mathrm{~N}_2]{\mathrm{NaNO}_2 / \mathrm{HCl}} \mathbf{Y}($ Tertiary alcohol $)+$ Other products

Find X and Y. Is y optically active? Write all the intermediate steps.

Give reasons :

In the following reaction sequence :

Identify A, B, C and D. Also write chemical equations for cons version of A to B and A to C.