RHYS LEWIS & MINH TAN PHAM, AHS, DECD, UNISA / SCIENCE PHOTO LIBRARY RHYS LEWIS & MINH TAN PHAM, AHS, DECD, UNISA / SCIENCE PHOTO LIBRARY
Geiger counter detecting alpha particles emitted by a disc of polonium 210 (red), a radioactive isotope of the element. Alpha particles are helium nuclei (two protons and two neutrons) emitted by unstable atomic nuclei. They are only able to travel a few centimetres through the air and are unable to penetrate even thin materials.
Model release not required. Property release not required.