The hydrogen-like species $\mathrm{Li}^{2+}$ is in a spherically symmetric state $\mathrm{S}_{1}$ with one radial node. Upon absorbing light the ion undergoes transition to a state $\mathrm{S}_{2}$. The state $\mathrm{S}_{2}$ has one radial node and its energy is equal to the ground state energy of the hydrogen atom. The state $\mathrm{S}_{1}$ is

JEE Advanced · 2010 · 11 Apr 2010 · Paper 2 · Atomic Structure

The hydrogen-like species

Li^{2 +}

is in a spherically symmetric state

S_{1}

with one radial node. Upon absorbing light the ion undergoes transition to a state

S_{2}

. The state

S_{2}

has one radial node and its energy is equal to the ground state energy of the hydrogen atom.

The state

S_{1}

(A)1s
(B)2s✓ Correct
(C)2 p
(D)3 s

Answer: (B)

Solution

A spherically symmetric state means l=0 (s orbital). The number of radial nodes = n - l - 1. For one radial node: n - 0 - 1 = 1, so n = 2. Therefore, S₁ is the 2s state.

JEE Advanced · 2010 · 11 Apr 2010 · Paper 2 · Single correct option

Practise more: all JEE Advanced PYQs on Atomic Structure →

More JEE Advanced questions on Atomic Structure

The 2s and the 2p orbital energies of hydrogen atom are $E_{2 s} (H)$ and $E_{2 p} (H)$ , respectively. The 2s and the 2p orbital energies of lithium atom are $E_{2 s} (Li)$ and …
JEE Advanced 2026View solution →
$X^{a +}$ and $Y^{b +}$ are hydrogen-like species. The wavelength of light absorbed during the transition between the states with principal quantum numbers $n = 1$ and $n = 2$ of $X^{a +}$ is $λ$ . The wavelength of light absorb …
JEE Advanced 2026View solution →
Among the following, the correct statement(s) for electrons in an atom is(are)
JEE Advanced 2024View solution →
According to Bohr's model, the highest kinetic energy is associated with the electron in the :
JEE Advanced 2024View solution →
For $He^{+}$ , a transition takes place from the orbit of radius 105.8 pm to the orbit of radius 26.45 pm.
The wavelength (in nm) of the emitted photon during the transition is ____.
[Use:
Bohr radius, $a = 52.9$ pm
Rydberg constant, …
JEE Advanced 2023View solution →
Consider a helium (He) atom that absorbs a photon of wavelength 330 nm . The change in the velocity (in $cm s^{- 1}$ ) of He atom after the photon absorption is ____.
(Assume: Momentum is conserved when photon is absorbed.
Use: Planck constant …
JEE Advanced 2021View solution →