Relative Ionising Effects
Physics: Cambridge International GCSE Supplement, topic 5.3.2
Relative Ionising Effects
Alpha particles
- They have moderate kinetic energy but a large mass, so they lose energy quickly in collisions.
- Their +2 electric charge gives them a strong attraction to electrons, so they ionise atoms very easily.
Beta particles
- They are much lighter and faster than alphas, with higher kinetic energy per particle, but they transfer less energy in each collision.
- Their –1 charge means they interact less strongly than alpha particles, so their ionising effect is weaker.
Gamma rays
- They have no mass, so their energy is carried as electromagnetic waves, which are less likely to directly collide with electrons.
- They have no charge, so they interact only weakly with matter, making them the least ionising of the three.
Test yourself on Relative Ionising Effects
Which of the following are true of penetration and ionisation?
Types of Emission
Types of Emisison
Which is the most penetrating form of radiation?