Atomic Structure

The Bohr radius of a hydrogen like species is 70.53 pm. The species and the stationary state (n) are respectively (Given : Hydrogen atom Bohr radius is 52.9 pm)

The surface of sodium metal is irradiated with radiation of wavelength $x$ nm. The kinetic energy of ejected electrons is $2.8\times10^{-20}$ J. The work function of sodium is 2.3 eV. The value of $x$ is ______ $\times10^2$ nm. (Nearest integer) (Given : $h=6.6\times10^{-34}$ J s; 1 eV $=1.6\times10^{-19}$ J; $c=3.0\times10^8$ m s$^{-1}$)

What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?

Which of the following is correct set of 4 quantum numbers of 19th electron in Chromium (Atomic number $=24$) in accordance with Aufbau principle?

The species having identical radii according to the Bohr's theory are: A. H (first orbit) B. $\mathrm{He^+}$ (first orbit) C. $\mathrm{He^+}$ (Second orbit) D. $\mathrm{Li^{2+}}$ (first orbit) E. $\mathrm{Be^{3+}}$ (Second orbit). Choose the correct answer from the options given below:

Arrange the following atomic orbitals of multi electron atoms in order of increasing energy. A. $n = 3, l = 2, m = +1$ B. $n = 4, l = 0, m = 0$ C. $n = 6, l = 1, m = 0$ D. $n = 5, l = 1, m = +1$ E. $n = 2, l = 1, m = +1$. Choose the correct answer from the options given below:

Identify the correct statements from the following : A. Heisenberg uncertainty principle is applicable to electrons. B. The size of $2p_x$ orbital is less than the size of $3p_x$ orbital. C. The energy of 2s orbital of H atom is equal to the energy of 2s orbital of Li. D. The electronic configuration of Cr is $[\mathrm{Ar}]\,3d^5\,4s^1$. Choose the correct answer from the options given below:

Which of the following statement(s) is/are true ? A. If two orbitals have the same value of $(n+l)$, the orbital with lower value of $n$ will have lower energy. B. Energies of the orbitals in the same subshell increase with increase in atomic number. C. The size of $2p_x$ orbital is less than the size of $3p_x$ orbital. D. Among 5f, 6s, 4d, 5p and 5d orbitals, none of the orbitals have 2 radial nodes. Choose the correct answer from the options given below :

If shortest wavelength of hydrogen atom in Lyman series is $x$, then longest wavelength in Balmer series of $\mathrm{He^+}$ is:

Match the LIST-I with LIST-II. List-I (Orbital): A. 2s; B. 3s; C. 3p; D. 4d. List-II (Radial nodes and nodal plane): I. 1 Radial node + two nodal planes; II. 1 Radial node + one nodal plane; III. 2 Radial nodes + No nodal plane; IV. 1 Radial node + No nodal plane. Choose the correct answer from the options given below: