Singly ionised helium (He ) has atomic number and contains a single orbiting electron…

CHEMISTRY · Multi-part · CBSE · Chemistry · Structure of Atom · Structure of Atom

Problem

Singly ionised helium (He

^{+}

) has atomic number

Z=2

and contains a single orbiting electron similar to hydrogen. (i) Specify the lower and upper principal quantum numbers that would give an emission line in He

^{+}

analogous to the hydrogen transition from the fourth to the second orbit. (ii) Calculate the wavelength of the photon emitted in this transition for He

^{+}

. (iii) Determine the ratio of this wavelength to the wavelength of the corresponding hydrogen line and state the spectral region (infrared, visible, ultraviolet, etc.) in which each of the two lines lies. (Use

R_{H}=1.097\times10^{7}\,\text{m}^{-1}

h=6.63\times10^{-34}\,\text{J\,s}

c=3.00\times10^{8}\,\text{m\,s}^{-1}

Related theory

Atomic Structure
Bohr's atomic model
Structure of Atom
Electron configurations
Bohr's Model of Atom

Browse the problem library