How is an atom ionized by electron impact?

[King E]

Can someone walk me through in detail what happens when an atom is ionized by colliding with an electron?

I would prefer a solid example so I can understand it more concretely.

What I think:

• The electron collides with the atom giving it energy, but then goes away after that.

• This energy excites an electron inside the atom, which receives enough energy to leave the atom.

• The atom is ionized.

However, I also thought of another way:

• The electron collides with the atom and gets bound up in the atom.

• The atom is now ionized (negative ion, since extra electron)

Are any of these descriptions correct?

[studiot]

This is a good non mathematical description.

say if you want something more technical.

https://www.radioactivity.eu.com/site/pages/Primary_Ionization.htm

look also at the page labelled

beta rays in matter

https://www.radioactivity.eu.com/site/pages/Beta_Rays_Matter.htm

[swansont]

1 hour ago, King E said:

Can someone walk me through in detail what happens when an atom is ionized by colliding with an electron?

I would prefer a solid example so I can understand it more concretely.

What I think:

• The electron collides with the atom giving it energy, but then goes away after that.

• This energy excites an electron inside the atom, which receives enough energy to leave the atom.

• The atom is ionized.

However, I also thought of another way:

• The electron collides with the atom and gets bound up in the atom.

• The atom is now ionized (negative ion, since extra electron)

Are any of these descriptions correct?

Both can happen. Electrons are subject to the electromagnetic interaction, so they can interact at a distance, and strip an electron off, as long as they possess sufficient energy to do so.

Low-energy electrons can also become bound to atoms, forming negative ions.

[King E]

23 minutes ago, swansont said:

Both can happen. Electrons are subject to the electromagnetic interaction, so they can interact at a distance, and strip an electron off, as long as they possess sufficient energy to do so.

Low-energy electrons can also become bound to atoms, forming negative ions.

Can you please explain that?

[swansont]

25 minutes ago, King E said:

Can you please explain that?

Electrons can become bound to an atom, but they have to lose energy to do so. Bound systems have a negative net energy (where potential energy is zero at infinite distance, and otherwise negative, owing to the net attraction)