Radioactivity
Physics: Cambridge International GCSE Supplement, topic 5.2.1
Radioactivity
An atom can have an unstable nucleus. An unstable nucleus can become more stable over time by randomly and spontaneously emitting ionising radiation. This process is called radioactive decay.
Radioactive substances
- Substances that decay radioactively are “radioactive substances”.
Decay is random and spontaneous
- Being random means that we cannot predict when an individual atom will emit (produce) ionising radiation.
- The direction of emission is random.
- Being spontaneous means that the process happens on its own, without any outside cause or trigger.
Test yourself on Radioactivity
How is radioactive decay triggered?
Which of the following are true of radioactive decay and nuclei?