Superactinide

The **superactinides** are a group of hypothetical elements predicted to be elements 121–156, one of which is expected to have a magic number of protons and neutrons – unbihexium. An isotope of unbihexium is expected to have 126 protons and 184 neutrons. Before the Superactinides, there are Ununennium and Unbinilium. As of 2025, none have been found. The elements in this block are considered g-block elements.

### Unbiunium

Unbiunium, also known as eka-actinium, was attempted to be synthesized in 1977 by  shooting Copper-65 at Uranium-238. It was unsuccessful and no atoms were identified.

### Unbibium

Unbibium, also known as eka-thorium, was attempted to be synthesized in 1972 by shooting Zirconium-66 and 68 at Uranium-238. It was unsuccessful and no atoms were detected. Unbibium is predicted to be in the island of stability.

### Unbitrium

Unbitrium also known as eka-protactinium, or element-123. No attempt has ever been made to make Unbitrium.

### Unbiquadium

Unbiquadium, also known as eka-uranium, is the predicted element-124. It is predicted that Unbiquadium-308 has a magic number of neutrons, 184. It is in the island of stability.

### Unbipentium

Unbipentium also known as eka-neptunium, is the predicted element-125. In 1977, Unbipentium was tried to be synthesized by shooting zinc-68 and 68 at americium-238. It was unsuccessful and no atoms were detected.

### Unbihexium

Unbihexium also known as eka-plutonium is expected to have a magic number of protons and neutrons 126 protons and 184 neutrons.
There was a synthesization attempt in 1971, however it was unsuccessful. It is in the island of stability.

### Unbiseptium

Unbiseptium, also known as eka-americium, was attempted to be synthesized in 1978 by shooting xenon ions at tantalum. No atoms were detected.

### Unbioctium

Unbioctium also known as eka-curium, is the predicted element-128, it has not been tried to be synthesized.

### Unbiennium

Unbiennium also known as element-129, has not yet been tried to be synthesized.

### Untrinilium

Untrinilium, also known as element-130, isotopes that are above Untrinilium are predicted to have isotopes that are extremely radioactive. It has never been tried to be synthesized.

### Untriunium

Untriunium, also known as eka-Einsteinium is element-131 of the periodic table. It has not yet been tried to be synthesized.

### Untribium

Untribium also known as eka-Rutherfordium is element-132 It is predicted to be in the island of stability.

### Untritrium

Untritrium, also known as element-133 has the atomic symbol Utt it is expected to have extremely unstable isotopes. It has not yet been tried to be synthesized.

### Untriquadium

Untriquadium, also known as element-134 is in the island of stability. It has not yet been tried to be synthesized.

### Untripentium

Untripentium, also known as element-135 has atomic symbol Utp. It has not yet been tried to be synthesized.

### Untrihexium

Untrihexium, also known as element-136 has not been tried to be synthesized. It has atomic symbol Uth.

### Untriseptium

Untriseptium also called eka-dubnium is predicted to be element-137. Richard Feynman said that Untriseptium located at the end of the periodic table. He was wrong. It turned out to be Unsepttrium. and there have not been any attempts to make Untriseptium.

### Untrioctium

Untrioctium, also known as element-138, has not yet been tried to be synthesized. It has atomic symbol Uto.

### Untriennium

Untriennium is element-139. It has not yet been tried to be synthesized. It has atomic symbol Ute.

### Unquadnilium

Unquadnilium is element-140. It has not yet been tried to be synthesized. It has atomic symbol Uqn.

### Unquadunium

Unquadunium is element-141 of the periodic table. It has not yet been tried to be synthesized, with the atomic symbol Uqu.

### Unquadbium

Unquadbium, is the predicted element-142. It is predicted to have extremely radioactive Isotopes. It has not yet been tried to be synthesized. It has atomic symbol Uqb.

### Unquadtrium

Unquadtrium, is the predicted element-143. It is predicted to have extremely radioactive Isotopes. It has never been tried to be synthesized. It has atomic symbol Uqt.

### Unquadquadium

Unquadquadium, is the predicted element-144. It has never been tried to be synthesized. It has atomic symbol Uqq.

### Unquadpentium

Unquadpentium, is the predicted element-145. It has never been tried to be synthesized.

### Unquadhexium

Unquadhxium, is the predicted element-146. It has never been tried to be synthesized. It has atomic symbol Uqh.

### Unquadseptium

Unquadseptium, is the predicted element-147. It has never been tried to be synthesized. It has atomic symbol Uqs.

### Unquadoctium

Unquadoctium, is the predicted element-148. It has never been tried to be synthesized. It has atomic symbol Uqo.

### Unquadennium

Unquadennium, is the predicted element-149. It has never been tried to be synthesized. It has atomic symbol Uqe.

### Unpentnilium

Unpentnilium, is the 150th element of the periodic table. It has not yet been tried to be synthesized.

### Unpentunium

Unpentunium, is the 151st element of the periodic table. It has not yet been tried to be synthesized.

### Unpentbium

Unpentbium, is the 152nd element of the periodic table. It has not yet been tried to be synthesized.

### Unpentrium

Unpentrium, is the 153th element of the periodic table. It has not yet been tried to be synthesized.

### Unpentquadium

Unpentquadium, is the 154th element of the periodic table. It has not yet been tried to be synthesized.

### Unpentpentium

Unpentpentium, is the 155th element of the periodic table. It has not yet been tried to be synthesized.

### Unpenthexium

Unpenthexium is the predicted element-156. It has not yet been tried to be synthesized.

### Unpentseptium

Unpentseptium is the last element in the superactinides. It is the predicted element-157. It has not yet been tried to be synthesized.

### Alpha decay chain

There is a alpha decay chain starting from 296-Uue,296 and 299-Ubn, 300-Ubu, 300 and 303-Ubb, 304-Ubt, and 304-Ubq continuing up a possible narrow 1 microsecond alpha decay chain. with targets 248-Cm 249-Bk and 249-Cf and projectiles 50-Ti 54-Cr and 58-Fe.

### Isotopes of Unbiunium

A calculation in 2016 predicted that the most stable predicted isotopes of Unbiunium are 309-314 Ubu. They are predicted to have half-lives long enough to be detected in labs. 304-314 Ubu though are expected to alpha decay.

### Isotopes of Unbibium

There were two attempts of making Ubb-306 they were tried to be made by shooting 58-Fe at 248-Cm. No atoms were found. The 2nd one was shooting 64-Ni at 242-Pu. Again, no atoms were found.

### Isotopes of Unbiquadium

The predicted most stable isotope of Unbiquadium is predicted to be Ubq-330. with 124 protons and 206 neutrons. Ubq-308 has a magic number of neutrons which is 184.

### Isotopes of Unbihexium

The predicted Ubh-310 expected to be the longest living isotope of Unbihexium. It has a magic number of protons and neutrons. 126 protons, and 184 neutrons.