# Application of Electromagnetism question

• kittyNoel
In summary, the Fe2+ ion moves faster than the Fe3+ ion through a magnetic field. The heavier ion has more protons and so has a greater electric potential energy which causes it to move faster.
kittyNoel

## Homework Statement

A sample of two different irons, Fe2+ and Fe3+, are accelerated by the same potential and then sent through the uniform magnetic field of a mass spectrometer.
a) Which ion moves faster after being accelerated? Justify your answer by referring to equations used in this lesson.

## Homework Equations

m = q(B^2)(r^2)/2

## The Attempt at a Solution

a)
Ee = Ek
Ee1 = 1/2 m1v1^2
Ee2 = 1/2 m2v2^2
1/2m1v1^2 = 1/2 m2v2^2

This means that the two particles both have the same potential energy... but one of the particles has more mass than the other... since it has more mass it takes more energy to move it and so moves slower...

This makes sense to me but how do I know which one has more mass? This answer also doesn't use the equation I included above which is the one from the unit that I think they want us to use...

c) The equation m = q(B^2)(r^2)/2 tells us that the heavier particles are deflected in an arc with a larger radius than lighter particles. This means that ____ (again I need to know which one is heaver) follows a path with a larger radius.

What do 2+ and 3+ mean? What is the difference between the Fe2+ and Fe3+ ions?

ehild

I think I typed that funny, probably should be Fe^2+ and Fe^3+ With the 2+ and 3+ being tiny and up at the top. I believe it is the charge of the element.

It is right, you have double charged and triple charged Fe ions. Is the mass of these ions appreciably different?

ehild

I'm not really sure... that's pretty much where I am stuck... they have to be different somehow otherwise why ask this question... I guess one has more protons than the other right because its more positive... so I guess it comes down to the tiny amount of extra mass that one of them has... you can't add protons to something... so to get the +2 charge you would have to have more electrons on it than the +3 charge... which would make it just a little bit heaver... right?

hi kittyNoel!

(ehild is offline, so i'll continue where he left off …)

sorry, but in concentrating on the mass you're completely missing the point

the difference in mass is negligible

what else is different about them that will affect the electromagnetic force?

I am back. The number of protons, the "atomic number" identifies an element. It is very hard to add a proton to a nucleus, and if you succeed, you get a different element. But it is easy to remove one or more outer electrons. If two or three electrons are removed, the Fe atom gains 2e or 3e positive charge. If the charge of the ions are different, their potential energies are different in an electric field. And check the equation for m in your first post: it is wrong.

ehild

I'm not sure about the equation that's what I see in my textbook.
What you said about the element is what I meant I just didn't explain it very well...

so where does this leave me? Is comparing them by there mass incorrect? I don't really know what's different about them except like you said one has more electrons than the other.

At potential V, what is the electric potential energy Ee of a charge q? How do you calculate the kinetic energy of a charged particle which is accelerated through a given potential difference?

ehild

Last edited:
hi kittyNoel!
kittyNoel said:
… one has more electrons than the other.

exactly! … so how does that effect the way it moves in an electric field?

## 1. What is Electromagnetism?

Electromagnetism is a branch of physics that deals with the study of the interactions between electrically charged particles. It includes the study of electric fields, magnetic fields, and how they are related to each other.

## 2. How is Electromagnetism applied in everyday life?

Electromagnetism has numerous applications in our daily lives, including the use of electric motors and generators, household appliances, radios, televisions, and computers. It is also essential in medical imaging technologies like MRI and X-rays.

## 3. How is Electromagnetism used in technology?

Electromagnetism is used in various technologies, such as telecommunications, satellite communication, and internet communication. It is also used in the production of electronic devices like smartphones, laptops, and GPS systems.

## 4. What are the main principles of Electromagnetism?

The main principles of Electromagnetism are Coulomb's Law, which describes the force between two electrically charged particles, and Ampere's Law, which explains the relationship between electric currents and magnetic fields. Additionally, Faraday's Law and Lenz's Law describe the induction of electric currents through changing magnetic fields.

## 5. How does Electromagnetism relate to other branches of science?

Electromagnetism is closely related to other branches of science, such as optics, which deals with the behavior of light, and thermodynamics, which studies the relationship between heat and energy. It also has connections to quantum mechanics, which explains the behavior of particles at the atomic level.

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