(A) Energy of photons: $E_1 = \frac{1240}{248} = 5 \ eV$ and $E_2 = \frac{1240}{310} = 4 \ eV$. Using Einstein's photoelectric equation: $K.E. = E - W

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(A) Energy of photons: $E_1 = \frac{1240}{248} = 5 \ eV$ and $E_2 = \frac{1240}{310} = 4 \ eV$. Using Einstein's photoelectric equation: $K.E. = E - W$. Given $u_1 : u_2 = 2 : 1$,the ratio of kinetic energies is $\frac{K.E._1}{K.E._2} = (\frac{u_1}{u_2})^2 = (\frac{2}{1})^2 = 4$. Therefore,$\frac{5 - W}{4 - W} = 4$. $5 - W = 16 - 4W$. $3W = 11$. $W = \frac{11}{3} \approx 3.67 \ eV \approx 3.7 \ eV$.

Class 11 Chemistry Structure of Atom Atomic models and Planck's quantum theory

Medium

$A$ metal surface is illuminated by light of two different wavelengths $248 \ nm$ and $310 \ nm$. The maximum speeds of the photoelectrons corresponding to these wavelengths are $u_1$ and $u_2$ respectively. If the ratio $u_1 : u_2 = 2 : 1$ and $hc = 1240 \ eV \ nm$,the work function of the metal is nearly $:-$ (in $eV$)

A
$3.7$
B
$3.2$
C
$2.8$
D
$2.5$

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Class 11

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Structure of Atom

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Atomic models and Planck's quantum theory

Circumference of the first orbit of hydrogen atom is given by the formula :

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In the spectrum of $Li^{2+}$,the difference between two energy levels is $2$ and their sum is $4$. Find the wavelength of the photon emitted during the transition between these two energy states.

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For hydrogen-like species,which of the following graphs provides the most appropriate representation of $E$ vs $Z$ plot for a constant $n$?
[$E$: Energy of the stationary state,$Z$: atomic number,$n$: principal quantum number]

DifficultJEE MAIN 2025

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The ratio of kinetic energies of photoelectrons emitted from a metal by light of frequencies $v_1$ and $v_2$ is $1 : 2$. The threshold frequency of the metal will be:

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If the wavelength of an electromagnetic radiation is $2000 \ \text{Å}$, what is its energy in ergs?

DifficultTS EAMCET 2003

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Circumference of the first orbit of hydrogen atom is given by the formula :

In the spectrum of $Li^{2+}$,the difference between two energy levels is $2$ and their sum is $4$. Find the wavelength of the photon emitted during the transition between these two energy states.

For hydrogen-like species,which of the following graphs provides the most appropriate representation of $E$ vs $Z$ plot for a constant $n$?[$E$: Energy of the stationary state,$Z$: atomic number,$n$: principal quantum number]

The ratio of kinetic energies of photoelectrons emitted from a metal by light of frequencies $v_1$ and $v_2$ is $1 : 2$. The threshold frequency of the metal will be:

If the wavelength of an electromagnetic radiation is $2000 \ \text{Å}$, what is its energy in ergs?

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For hydrogen-like species,which of the following graphs provides the most appropriate representation of $E$ vs $Z$ plot for a constant $n$?
[$E$: Energy of the stationary state,$Z$: atomic number,$n$: principal quantum number]