# The nature of cathode rays and canal rays

1. Oct 17, 2013

### DevPhysics

Hello everyone,
I have some questions about these rays. And i would be grateful if you could help me,

1- The nature of cathode rays doesnt depend on neither the gas in the tube nor the material of the electrodes. Why?

2-The nature of canal rays depends on the gas in the tube. Why?

3- Does the nature of canal rays also depend on the material of the electrodes?

Thank you and have a great day.

2. Oct 17, 2013

### Staff: Mentor

3. Oct 17, 2013

### DevPhysics

Hi dr,
This isn t for homework. These are some questions that stuck in my mind while studying.
And i have checked the links already. All of the questions are specific. And i couldn t find a proper answer. That is why i am asking these questions here
Thanks

4. Oct 17, 2013

### Staff: Mentor

Your first two questions can be answered by considering: what are cathode rays and canal rays composed of?

5. Oct 17, 2013

### DevPhysics

Thanks but this doesn t answer my questions properly. I have looked for the links as yoy said but all of them just says like "each gas gives different charge to mass ratio (anode rays) ..." I want to know "why".
Thanks

6. Oct 17, 2013

### Staff: Mentor

Say, you have samples of helium and argon. Say, each has been ionized by removing a single electron. Calculate mass/charge ratio. Are they identical?

7. Oct 17, 2013

### DevPhysics

Ooh so i am removing same number of electrons from the gases. In this case their charge will be the same (+1) but their mass will be different because of their proton and notron numbers (mass). But when it comes to cathode rays, if i increase the number electrons, their charge and mass ratio won t change. I get it now thank you so much.
And about the 3rd questions . So the nature of anode rays doesnt depend on the material of electrodes. It only depends on the gas right?

8. Oct 17, 2013

### Staff: Mentor

Actually it doesn't matter much how many electrons you remove. Check for several gases each loosing between 1 and - say - 5 electrons. Sometimes you will get close with the mass/charge ratio, but it won't be identical.

9. Oct 17, 2013

### DevPhysics

Sorry i didnt understand your message.I think i should ask like this" why charge to mass ratio is different for anode rays(+) while it is the same for cathode rays(-). Where do this come from?"
And what can you say about 3rd question?

Thank yo so much and have a great day.

10. Oct 17, 2013

### Staff: Mentor

You already know why it is different for anode rays. Now, what is the mass/charge ratio for cathode rays?

You are still missing the most important thing, one that DrClaude asked long ago - what are those rays? What they are defines what their properties are and answers all your questions.

11. Oct 17, 2013

### DevPhysics

The ratio is the same for cathode rays (negative particles/electrons) because electrons are common particles for every element. So their mass and charge ratio will be the same for every element. ( 1 charge for 1 mass/electron, 2 charge for 2mass/electrons) but when it comes to anode rays every element has different numbers of protons that affect their charge/mass ratio. Now everythings is clear. Thank yo so much!

And the last, i still couldnt find an answer for my 3rd question. What can you say about it? We know that the nature of anode(canal) rays depends on the gas used in the tube. But do canal rays also depend on the material of the electrodes? For example i have 2 canal ray tubes and they have the same gas inside them. But one has electrodes made with gold and the other one has silver electrodes. Does this affect the canal rays?

Have a great day!

12. Oct 17, 2013

### Staff: Mentor

Electrode is just an inert piece of metal.

13. Oct 18, 2013