Structure of Atom

If a0 is denoted as the Bohr radius of hydrogen atom, then what is the de Broglie wavelength (λ) of the electron present in the second orbit of hydrogen atom? [n : any integer]

1. 8 a0n
2. 2a0n
3. na04
4. 4 a0n

In a multielectron atom, which of the following orbitals described by three quantum numbers will have same energy in absence of electric and magnetic fields? Choose the correct answer from the options given below:

1. B and C Only
2. C and D Only
3. A and B Only
4. D and E Only

Which of the following is/are not correct with respect to energy of atomic orbitals of hydrogen atom? Choose the correct answer from the options given below :

1. (A) and (B) only
2. (A) and (C) only
3. (B) and (D) only
4. (C) and (D) only