Chemistry, asked by trishulramraoghaywat, 10 months ago

the work function for cs is 19ev calculate threshold frequency if cs metal is irradiated with wavelength of 5oonm

Answers

Answered by mvm9363
0

Answer:

The work function of cesium atom is 1.9 eV. Converting the unit in J.

1.9eV×1.602×10  

−19

J/eV=3.04×10  

−19

J

The threshold frequency is  

6.626×10  

−34

 

3.04×10  

−19

 

​  

=4.59×10  

14

 Hz.

The threshold wavelength is λ  

0

​  

=  

ν  

0

​  

 

c

​  

=  

4.59×10  

14

 

3.0×10  

8

 

​  

=6.54×10  

−7

 m.

The energy of radiated light is

E=  

λ

hc

​  

=  

500×10  

−9

 

6.626×10  

−34

×3×10  

8

 

​  

=3.98×10  

−19

J

The kinetic energy of ejected electron is

K.E=3.98×10  

−19

−3.04×10  

−19

=9.4×10  

−20

J=  

2

1

​  

mv  

2

 

v=  

m

2K.E

​  

 

​  

=  

2  

9.1×10  

−31

 

9.14×10  

−20

 

​  

 

​  

=4.54×10  

5

m/s

Explanation: thank you !!

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