English
Karnataka Board PUCPUC Science Class 11

If the photon of the wavelength 150 pm strikes an atom and one of its inner bound electrons is ejected out with a velocity of 1.5 × 107 ms–1,

Advertisements
Advertisements

Question

If the photon of the wavelength 150 pm strikes an atom and one of its inner bound electrons is ejected out with a velocity of 1.5 × 107 ms–1, calculate the energy with which it is bound to the nucleus.

Numerical
Advertisements

Solution 1

Energy of incident photon (E) is given by,

`E = ("hc")/lambda`

`= ((6.626xx10^(-34) " Js")(3.0 xx 10^8 " ms"^(-1)))/(150xx10^(-12) " m")`

`= 1.3252 xx 10^(-15)` J

`= 13.252 xx 20^(-16)` J

Energy of the electron ejected (K.E)

`= 1/2 "m"_"e""v"^2`

`=1/2(9.10939xx10^(-31) " kg")(1.5 xx 10^7 " ms"^(-1))^2`

= 10.2480 × 10–17 J

= 1.025 × 10–16 J

Hence, the energy with which the electron is bound to the nucleus can be obtained as:

= E – K.E

= 13.252 × 10–16 J – 1.025 × 10–16 J

= 12.227 × 10–16 J

`= (12.227xx10^(-16))/(1.602xx10^(-19))` eV

`= 7.6 xx 10^3` eV

`(5lambda_0 - 2000)/(4lambda_0 - 20000) = (5.35/2.55)^2 = 28.6225/6.5025`

`(5lambda_0 - 2000)/(4lambda_0- 2000) = 4.40177`

`17.6070lambda_0 - 5lambda_0 = 8803.537- 2000`

`lambda_0 = (6805.537)/12.607`

`lambda_0 = 539.8 "nm"`

`lamda_0 = 540 "nm"`

shaalaa.com

Solution 2

Energy of the incident photon= hc/λ = (6.626×10-34 Js×3.0×108 ms-1)/(150×10-12m) = 13.25×10-16 J

Energy of the electron ejected = 1/2 mv2 = 1/2×(9.11×10-31kg)×(1.5×107ms-1)2 = 1.025×10-16 J

Energy with which the electron was bound to the nucleus = 13.25×10-16 J - 1.025×10-16 J

= 12.225×10-16 J = 12.225×10-16/1.602×10-19 eV = 7.63×103 eV

shaalaa.com
  Is there an error in this question or solution?
Chapter 2: Structure of Atom - EXERCISES [Page 72]

APPEARS IN

NCERT Chemistry Part 1 and 2 [English] Class 11
Chapter 2 Structure of Atom
EXERCISES | Q 2.54 | Page 72

RELATED QUESTIONS

Find the frequency of revolution of an electron in Bohr’s 2nd orbit; if the radius and speed of electron in that orbit is 2.14 × 10-10 m and 1.09 × 106 m/s respectively. [π= 3.142]


What is the maximum number of emission lines when the excited electron of an H atom in n = 6 drops to the ground state?


Calculate the radius of Bohr’s fifth orbit for hydrogen atom


In accordance with the Bohr’s model, find the quantum number that characterises the earth’s revolution around the sun in an orbit of radius 1.5 × 1011 m with orbital speed 3 × 104 m/s. (Mass of earth = 6.0 × 1024 kg)


In Bohr’s model of the hydrogen atom, the radius of the first orbit of an electron is r0 . Then, the radius of the third orbit is:

a) `r_0/9`

b) `r_0`

c) `3r_0`

d) `9r_0`


Using Bohr’s postulates, obtain the expression for the total energy of the electron in the stationary states of the hydrogen atom. Hence draw the energy level diagram showing how the line spectra corresponding to Balmer series occur due to transition between energy levels.


According to Maxwell's theory of electrodynamics, an electron going in a circle should emit radiation of frequency equal to its frequency of revolution. What should be the wavelength of the radiation emitted by a hydrogen atom in ground state if this rule is followed?


In which of the following systems will the wavelength corresponding to n = 2 to n = 1 be minimum?


Hydrogen atom has only one electron, so mutual repulsion between electrons is absent. However, in multielectron atoms mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms?


Derive an expression for the frequency of radiation emitted when a hydrogen atom de-excites from level n to level (n – 1). Also show that for large values of n, this frequency equals to classical frequency of revolution of an electron.


The ratio of the ionization energy of H and Be+3 is ______.


If a proton had a radius R and the charge was uniformly distributed, calculate using Bohr theory, the ground state energy of a H-atom when (i) R = 0.1 Å, and (ii) R = 10 Å.


Find the ratio of energies of photons produced due to transition of an election of hydrogen atom from its (i) second permitted energy level to the first level. and (ii) the highest permitted energy level to the first permitted level.


A 100 eV electron collides with a stationary helium ion (He+) in its ground state and exits to a higher level. After the collision, He+ ions emit two photons in succession with wavelengths 1085 Å and 304 Å. The energy of the electron after the collision will be ______ eV.

Given h = 6.63 × 10-34 Js.


What is the energy associated with first orbit of Li2+ (RH = 2.18 × 10-18)?


According to Bohr's theory, the radius of the nth Bohr orbit of a hydrogen like atom of atomic number Z is proportional to ______.


Oxygen is 16 times heavier than hydrogen. Equal volumes of hydrogen and oxygen are mixed. The ratio of speed of sound in the mixture to that in hydrogen is ______.


An electron in a hydrogen atom has an energy of -3.4 eV. The difference between its kinetic and potential energy is ______.


Using Bohr’s Theory of hydrogen atom, obtain an expression for the velocity of an electron in the nth orbit of an atom.


Which law of force governs the nucleus-electron system?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×