The Actinide series.
Radioactive elements exist in all groups of the periodic table.
The family of radioactive elements is called the Actinides. This group includes elements such as uranium, thorium, and plutonium, which are known for their radioactive properties.
After disintegration all radioactive elements are transformed in other elements.
This family is called, after IUPAC nomenclature -- actinoids.
The Actinide series.
Not all of the transition elements are radioactive. Many of them are, and some of them have common radioactive isotopes, but some of them have no naturally occurring radioactive isotopes. Please note that all elements have synthetic radioactive isotopes, at least.
Radioactive elements make up a small fraction of all naturally occurring elements in Earth's crust. Most elements are stable and non-radioactive. However, even though they are a minority, radioactive elements play important roles in various scientific, medical, and industrial applications.
Radioactive elements exist in all groups of the periodic table.
All elements comprising the period 7 in the periodic table are radioactive. In total this period has 32 elements.
Usually not, but all elements have radioactive isotopes.
None - they are all radioactive.
Oh, dude, let me break it down for you. So, the three families that contain no radioactive elements are the noble gases, the alkaline earth metals, and the alkali metals. It's like they're the cool kids who don't mess around with that radioactive drama. Just chillin' with their stable atomic structures, you know?