Why does an α particle cause more ionisation than a β particle if they have the same kinetic energy?

An alpha particle has a much larger volume than a β particle, so when passing by an atom it is more likely to collide with an electron and knock it out of the atom causing the atom to be ionised (meaning it is now an ion) and so more ions are created, making it more ionising than a β particle. Another reason why α particles cause more ionisation is because it has more charge. An α particle has a charge of +2, which is the opposite charge to the electrons orbiting the atoms, so the α particle attracts the electrons and pulls them away from the atom, leaving it with fewer electrons, making it an ion. On the other hand, β particles are electrons, so they have the same charge as the electrons orbiting the atom, so they will only push electrons back towards the atom, meaning it is unlikely that β particles iononise through this method.

Answered by Physics tutor

6959 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A rocket travels with constant velocity in a straight line in deep space. A ball is thrown from the back to the front (ie from the thrusters to the nose). Describe the path of the ball. Describe the path if the rocket were accelerating along this line.


How does a thermal nuclear reactor work?


Describe the photoelectric effect.


You have a layer of glass with a refractive index of 1.5 and the glass is surrounded by air. A light ray shines into the glass and Total Internal Reflection occurs at the glass-air boundary. What is the critical angle?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning