Photoelectric Cells: What Are They and Why Evacuated?

  • Thread starter Thread starter bael
  • Start date Start date
  • Tags Tags
    Cell
Click For Summary

Discussion Overview

The discussion centers on the functioning of photoelectric cells, specifically addressing the reason for their evacuated design. Participants explore the implications of gas presence on electron movement and current measurement.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant questions the necessity of evacuation in photoelectric cells, prompting others to consider the mechanics of electron movement.
  • Another participant elaborates on the process, noting that light of a certain frequency can free electrons from a metal surface, which then travel towards the positive cathode.
  • There is a suggestion that the presence of gases like oxygen could lead to collisions with electrons, potentially ionizing the gases and affecting current readings.
  • A later reply reiterates the concern that such collisions could result in no current reading at all.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the reasons for evacuating photoelectric cells, with multiple viewpoints regarding the impact of gas presence on electron behavior and current measurement remaining unresolved.

Contextual Notes

The discussion does not clarify the specific mechanisms by which gas presence affects electron movement or current readings, leaving assumptions about the nature of collisions and ionization unaddressed.

bael
Messages
28
Reaction score
0
I was wondering why photoelectric cells are evacuated
 
Chemistry news on Phys.org
Think how they work.
 
Borek said:
Think how they work.

light of a certain frequency hits a metal and frees some electrons, which then travel toward the positive cathode.
 
So far so good. Now think about the "travel towards the cathode part".
 
Borek said:
So far so good. Now think about the "travel towards the cathode part".

is it because the electrons could possibly collide with the oxygen and other electronegative gases, ionizing them and thus giving a smaller reading on the current meter?
 
bael said:
is it because the electrons could possibly collide with the oxygen and other electronegative gases, ionizing them and thus giving a smaller reading on the current meter?

More precisely "giving no reading".
 

Similar threads

Potential across a battery cell change ion concentrations and electron flow
  • · Replies 4 ·
Replies
4
Views
2K
Do we need salt bridges in Electrolytic cells?
  • · Replies 3 ·
Replies
3
Views
2K
Are atomic conductivity and standard reduction potential correlated?
  • · Replies 5 ·
Replies
5
Views
2K
Galvanic cells: H+ vs H2SO4, and Br2(aq) vs Br2(l)
  • · Replies 2 ·
Replies
2
Views
2K
What is the true voltage of a voltaic cell?
  • · Replies 10 ·
Replies
10
Views
3K
Undergrad How Do Photoelectric Cells Capture Color and Light Intensity?
  • · Replies 3 ·
Replies
3
Views
3K
How much electrical energy can be extracted from Iron in a cell?
  • · Replies 3 ·
Replies
3
Views
2K
Electrochemistry and cell electroplating
  • · Replies 4 ·
Replies
4
Views
2K
Clarification about the sign of EMF in batteries and electrochemistry
  • · Replies 3 ·
Replies
3
Views
3K
Galvanic cell - open circuit voltage and EMF
  • · Replies 23 ·
Replies
23
Views
6K