All elements have at least some radioactive isotopes.
For some elements no radioactive isotopes are known except those that are synthetic (see link to related question below).
For some other elements, there are both radioactive isotopes and stable isotopes in nature. (see link to related question below).
Some elements only have radioactive isotopes, and these are found in nature in at least trace quantities, they include (ordered by atomic number; those marked with * are normally only found in trace amounts in ore as radioactive decay products, and those with ** are distributed radioactive decay products found in trace amounts):
Period 5: technetium*
Period 6: promethium*, bismuth, polonium*, astatine*, radon**
Period 7: francium*, radium*, actinium*, thorium, protactinium*, uranium, neptunium*, plutonium**
The fact that all isotopes of bismuth are radioactive was only recently discovered.
Some elements are only know as a result of synthesis by human activity, and these are as follows:Period 7: americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, lawrencium, rutherfordium, dubnium, seaborgium, bohrium, hassium, meitnerium, darmstadtium, roentgenium, copernicium, and anything new that might come along.
Some examples of radioactive elements on the periodic table include uranium, thorium, radium, and plutonium. These elements have unstable atomic nuclei that decay over time, emitting radiation in the process.
it was found in 1896. you can not find them on the periodic table. you may find some, but often some are.
The actinoids (formerly actinides) are all unstable metallic elements. The period 7 elements with atomic numbers from 89 (actinium, for which the group is named) through 103 comprise these elements. A link can be found below.
In the Periodic Table of Elements there are: 118 Observed Elements 114 Officially Discovered Elements 112 Officially named Elements 92 Naturally Occuring Elements 83 Non-radioactive elements
Radioactive elements do not have a specific chemical formula, as they can be any element on the periodic table with unstable nuclei that emit radiation. Some examples of radioactive elements include uranium, radium, and thorium.
Group 3 of the periodic table contains many of the radioactive elements.
Radioactive elements exist in all groups of the periodic table.
Radioactive elements exist in all groups of the periodic table.
Some examples of radioactive elements on the periodic table include uranium, thorium, radium, and plutonium. These elements have unstable atomic nuclei that decay over time, emitting radiation in the process.
it was found in 1896. you can not find them on the periodic table. you may find some, but often some are.
all elements after uranium (atomic number 92) are radioactive.
Radioactive atoms can be found throughout the periodic table. They can be naturally occurring elements like uranium and thorium, or they can be created synthetically in laboratories by bombarding stable atoms with particles.
Some radioactive elements in the periodic table are radium, uranium, plutonium, thorium, polonium, radon, francium, astatine, radium, and curium.
Lanthanides and Actinides probably
Radioactive substances are not exclusive to the last period of elements on the periodic table, but many of the heaviest elements, particularly those in the actinide and transactinide series, are radioactive. These elements, found at the bottom of the periodic table, typically have unstable nuclei that decay over time. However, there are also radioactive isotopes of lighter elements scattered throughout the periodic table. Thus, while many radioactive elements are at the bottom, not all radioactive substances belong to this category.
All elements comprising the period 7 in the periodic table are radioactive. In total this period has 32 elements.
This is hard to answer.All elements have radioactive isotopes.Some elements have no known stable isotopes.It might be more instructive to put the periodic table aside and look at a table of nuclides instead. There's a link to one in the Related Links section.