In 1902 Ernest Rutherford and Frederick Soddy discovered that radioactive elements, such as uranium and thorium, broke down into other elements in a predictable sequence or series. This amazing ...

The discovery of radioactivity allowed scientists to develop new methods of determining Earth's age, with astonishing results. Our planet is far older than people had thought! Students can ...

In this lesson, students will investigate the nature of radioactivity and the effect of both distance and shielding materials on different radioactive sources using a Geiger-Muller tube with a counter ...

Radioactive decay is a spontaneous and random process. A block of radioactive material will contain many trillions of nuclei and not all nuclei are likely to decay at the same time so it is ...

A spontaneous process means that it is not possible to say which particular nucleus will decay next, but given that there are so many of them, it is possible to say that a certain number will ...