The actinides are the 14 elements from thorium (atomic number 90) to lawrencium (atomic number 103). The actinide series is much different. Actinoid element, also called actinide element, any of a series of 15 consecutive chemical elements in the periodic table from actinium to lawrencium (atomic numbers 89–103). what block are actinides in? There are 15 elements in the Actinide series. Actinides are a series of radioactive elements, which are metals. Actinides represent a family of 15 elements on the periodic table in period 7. As a group, they are significant largely because of their radioactivity.Although several members of the group, including uranium (the most familiar), occur naturally, most are man-made. Lanthanide and Actinide Series are both referred to as Rare Earth Metals. The actinides (or actinoids) are the chemical elements with atomic numbers between 90 and 109 inclusively. Actinides is a set of elements in the periodic table with the atomic numbers ranging from 90 to 103. Actinide Series of Metals There are two rows under the periodic table: the lanthanide and actinide series. Side by Side Comparison – Actinides vs Lanthanides in Tabular Form 5. All of the others have only been artificially made in … All of these elements, except Actinium, Thorium, Protactinium and Uranium are only made artificially and are not found in nature. They are all radioactive and some are not found in nature. are actinides found free in nature? Actinides occur between Groups 3 and 4 in Period 7 of the periodic table.All elements in this family are radioactive (that is, they spontaneously release subatomic particles or energy as their nuclei decay). The actinides are all radioactive elements and only the first four have been found naturally on Earth. (An atomic number indicates the number of protons in an atom.) What are Actinides 3. Only one element in the series is radioactive. Lanthanide and Actinide Series are both referred to as Rare Earth Metals. All elements in this family are radioactive (that is, they spontaneously release subatomic particles or energy as their nuclei decay). Actinides A class of very heavy radioactive nuclei. The Actinide series contains elements with atomic numbers 89 to 103 and is the sixth group in the periodic table. The lanthanide series can be found naturally on Earth. The series is the row below the Lanthanide series, which is located underneath the main body of the periodic table. What are Actinides? what are two other characteristics of actinides? The series is the row below the Lanthanide series, which is located underneath the main body of the periodic table. Ac is not actually a part in this group of element all are radioactive. Summary. Actinides occur between Groups 3 and 4 in Period 7 of the periodic table. Alongside the fission products found in the core of nuclear reactors there are elements known as actinides, heavy nuclei that also contribute to the radioactivity of the spent fuel.These 'transuranic' nuclei, heavier than uranium, are produced by neutron captures which do not lead to nuclear fission. The Actinide series contains elements with atomic numbers 89 to 103 and is the third group in the periodic table. Actinides. Five actinides have been found in nature: thorium, protoactinium, uranium, neptunium, and plutonium. only the first four elements (Th, Pa, U, Np) are found naturally, the rest are lab-made. The 5 f sublevel is in the process of being filled. What are Lanthanides 4. The atomic number of these elements range from 89 to 103 while the atomic masses range from 227 to 262g/mol. on 5f.