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The work function for caesium atom is 1.9 eV. Calculate (a) the thr...

The work function for caesium atom is 1. | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom NCERT Solutions

Question:

The work function for caesium atom is 1.9 eV. Calculate

(a) the threshold wavelength and

(b) the threshold frequency of the radiation. If the caesium element is irradiated with a wavelength 500 nm, calculate the kinetic energy and the velocity of the ejected photoelectron.

Answer:

A) Work function of caesium (WO) = hv_o

Therefore v_o = W_O/h = 1.9 x1.602 x10^-19/ 6.626x10^-34

= 4.59x10¹⁴/sec

B) λ_o =c/v_o = 3x10⁸/ 4.59x10¹⁴ = 6.54x10^-7m

C) K.E of ejected electron = h(v-v_o) = hc(1/λ – 1/ λ_o)

=(6.626x3x10^-26) (1/500x10^-9 – 1/654x10^-9)

=(6.626x3x10^-26) / 10^-9(154/500x654)

= 9.36x10^-20J

k.E = 1mv²/2 = 9.36x10^-20J

=9.1x10^-31/2 = 9.36x10^-20J

v2 = 20.55x10¹⁰m²s^-2

v = 4.53x10⁵ms^-1

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Comments

Vansh
2019-12-19 05:59:26

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Jash
2019-07-28 12:49:00

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Mayukh
2019-05-24 23:06:50

A really smart answer!

Khushi
2019-01-24 19:48:31

It's very helpful thanks....

Garvit
2018-07-10 17:27:02

Galat h

renu
2018-07-06 15:58:42

Thanks for helping us

vijayvijay
2018-06-16 12:36:03

thanks for helping me

Khatri
2018-05-27 21:41:55

Nyc solution

Rakshan
2017-08-03 22:19:17

Bakwas

MHYT
2017-06-15 19:26:04

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Welcome to the NCERT Solutions for Class 11 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 51: The work function for caesium atom is 1.9 eV. Calculate (a) the threshold wavelength and (b) t....

The work function for caesium atom is 1. | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom NCERT Solutions

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