Wave Functions & Probability
Physics: IB Diploma Higher Level, topic 5.3.5
Wave Functions & Probability
At the quantum level, particles such as electrons and alpha particles can be represented by a wave function.
Probability
- In quantum mechanics, a particle’s trajectory and destination cannot be precisely predicted for each particle individually.
- This is due to the wave behavior of matter as formulated by de Broglie.
- It makes sense to instead investigate the distribution of probabilities of a particle being in certain locations.
Probability 2
- There is a small, nonzero chance that an alpha particle will be located far away from its original location inside the nucleus.
- There is a small probability each second of the alpha particle being found at this new position, effectively resulting in alpha decay.
- The greater this probability, the less time it takes to happen and thus, the shorter the half-life of the decay sequence.
Wave function
- The wave function represents the probability of finding the particle at a given precise location.
- A particle with a wave function that is spread out in space is more likely to be found further away from the place we expect it to be.
- A particle with a wave function that is narrow is more likely to be found close to the place we expect it to be.
Test yourself on Wave Functions & Probability
Which of the following objects is NOT described by a wave function?
Which of the following properties of wavefunctions best describes that of a particle likely to undergo alpha emission?