Physics Paper 1 · P4 · Lesson 4.5
Meet unstable nuclei, radiation and the detector that counts it.
An unstable nucleus can give out radiation as it changes towards a more stable state. This is radioactive decay. The radiation comes from the nucleus. Sources may emit alpha, beta, gamma or neutrons.
Radioactive does not mean that a material glows or feels hot.
No timer. Read the explanation after each answer.
Daily 5 · Core exam practice · Higher Tier questions · A4 revision sheet
Lessons 4.1–4.10 cover the core. Lesson 4.11 is Higher Tier only. Daily 5 practises core facts. Answer positions are shuffled on each new attempt; lessons begin with very simple questions.
AQA Combined Science Trilogy specification · 6.4.2.1. Original notes, questions and diagrams. Experimental numbers are illustrative.
Photos: Geiger counter by Boffy b, enhanced by Marco Plassio; caesium source by Wusel007, enhanced by Partynia, both CC BY-SA 3.0. Rutherford at McGill, 1905, unknown photographer / Wellcome Images, public domain. Photos displayed without cropping or other alterations.
