Summary Photoelectric effect IEB Notes

-Photoelectric Effect-


Light has particle duality
·




-


Travels as a wave


-


Interacts as particle


t= E High frequency = low
wavelength


f
-
o
Frequency (H2)-

Speedoflight -I
--------




Energy directly proportional to frequency
·




-Energy _
of Photon
-




ha
E = hf or E = X




E Energy of photon

↓ & Planck's constant (6 6 ,
.
10 J .
5)



-Electron Volt -




Unit of
·



energy
·
1 6 ,
.
1819J
eV to
·

joules
-
19
X
by 1 6
-


10
.


,




Joules to
·

eV
%9
-
-
by 1 6 ,
.

10




-PhotoelectricEffect -
* Photoelectrons #


F
Light shines on metal and electrons are ejected
----------------
- - -

7
·
Loosens electrons on surface I
E = Wo + El (max) I

I
I
-Minumum is recquired I
energy
or
I

Wo ho I
Threshold frequency Work function
frequency of incident radiation
· a
: minimum =

I

which electrons will be emmited from a particular metal at
I
I

-



Corresponds to wavelength (maximum wavelength(
El
I
(max) &
Energy of emitted electron = meV Y
-



Threshold frequency = fo I I

10
Increased intensity (more photons) :
I
me Mass of electron 19 , 1 .




kg) I

I I
↳ More electrons ejected per second
I I

Increased frequency ↓ velocityoemitted electro
I
↓ -
-
---

Increased Kinetic energy of photoelectron
↳




·
Work function : minimum amount of needed to emit
energy
an electron from the surface of a metal

-

Loosens electrons from bond

Move into surface conduction band
-




Any additional transforms to kinetic
energy energy