Question
A positive ion having just one electron ejects it if a photon of wavelength $288\mathring{\text{A}}$ or less is absorbed by it. Identify the ion.
✓
Answer
$\lambda=228\mathring{\text{A}}$
$\text{E}=\frac{\text{hc}}{\lambda}=\frac{6.63\times10^{-34}\times3\times10^{8}}{228\times10^{-10}}=0.0872\times10^{-16}$
The transition takes place form n = 1 to n = 2
Now, ex. $\frac{13.6\times3}{4\times\text{z}^2}=0.0872\times10^{-16}$
$\Rightarrow\text{z}^2=\frac{0.0872\times10^{-16}}{13.6\times3\times1.6\times10^{-19}=5.3}$
$\Rightarrow\text{z}=\sqrt{5.3}=2.3$
The ion may be Helium.
$\text{E}=\frac{\text{hc}}{\lambda}=\frac{6.63\times10^{-34}\times3\times10^{8}}{228\times10^{-10}}=0.0872\times10^{-16}$
The transition takes place form n = 1 to n = 2
Now, ex. $\frac{13.6\times3}{4\times\text{z}^2}=0.0872\times10^{-16}$
$\Rightarrow\text{z}^2=\frac{0.0872\times10^{-16}}{13.6\times3\times1.6\times10^{-19}=5.3}$
$\Rightarrow\text{z}=\sqrt{5.3}=2.3$
The ion may be Helium.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
→→→→→→→→→
The. wire ABC shown in figure forms an equilateral triangle. Find the magnetic field B at the centre O of the triangle assuming the wire to be uniform.
Obtain the formula for force acting between two parallel straight current carrying conductors and hence define one ampere.
A particle of mass m moves on a straight line with its velocity varying with the distance travelled according to the equation $\text{v}=\text{a}\sqrt{\text{x}},$ where a is a constant. Find the total work done by all the forces during a displacement from x = 0 to x = d.
→Locate the image of the point P as seen by the eye in the figure.
Explain the construction of refracting telescope by figure and obtain the equation of magnification.
Obtain the equation of electric current for an AC circuit having only inductor.
A particle of mass ‘m’, with charge ‘q’ moving with a uniform speed ‘v’, normal to a uniform magnetic field ‘B’, describes a circular path of radius ‘r’. Derive expressions for the:
- Time period of revolution.
- Kinetic energy of the particle.
A charge of 3.14 × 10-6C is distributed uniformly over a circular ring of radius 20.0cm. The ring rotates about its axis with an angular velocity of 60.0 rad/s. Find the ratio of the electric field to the magnetic field at a point on the axis at a distance of 5.00cm from the centre.