The promethium has the 18 nuclear isomers with the mass number of 133 to 142, 144, 148, 152, and 154. The most stable isotope is promethium-148 which has a half-life of $43.1$ days. Thus, from given lanthanides, only promethium $\text{ (Pm) }$can undergo the decay and it is radioactive.
Which is the only lanthanide which is radioactive?
Promethium
Promethium is one of only two radioactive elements that are followed in the periodic table by elements with stable forms, the other being technetium. Chemically, promethium is a lanthanide. Promethium shows only one stable oxidation state of +3.
Is promethium a radioactive element?
Promethium is very radioactive and emits beta radiation, according to Lenntech. According to Chemicool, metallic promethium is silvery white, and the salts glow in the dark with a pale blue or green light.
Are all the lanthanides radioactive?
The series is the row below the Lanthanide series, which is located underneath the main body of the periodic table. Lanthanide and Actinide Series are both referred to as Rare Earth Metals. These elements all have a high diversity in oxidation numbers and all are radioactive.
Which is the only radioactive element in the transition elements group?
Technetium is a chemical element with the symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive.
What is special about technetium and promethium?
Technetium, with atomic number (denoted Z) 43, is the lowest-numbered element in the periodic table that is exclusively radioactive. The second-lightest, exclusively radioactive element, promethium, has an atomic number of 61.
Why promethium and its compounds do not occur in nature?
Promethium has no known biological role. Promethium’s longest-lived isotope has a half-life of only 18 years. For this reason it is not found naturally on Earth.
Is promethium the strongest metal?
Superman flies off to his Fortress of Solitude, where the analysis reveals that Metallo contains promethium, the “strongest metal known to man,” according to the analysis. They could use the radioactive signature of promethium to track Metallo.
Is promethium a reactivity?
Reaction of promethium with water
However, one would predict that the silvery white metal promethium is quite electropositive and would react slowly with cold water and quite quickly with hot water to form promethium hydroxide, Pm(OH)3, and hydrogen gas (H2).
What does promethium decay into?
neodymium-145
Promethium does not occur naturally on earth, although it has been detected in the spectrum of a star in the constellation Andromeda. Promethium’s most stable isotope, promethium-145, has a half-life of 17.7 years. It decays into neodymium-145 through electron capture.
Where are most of the radioactive elements on the periodic table?
All of the elements from element 84 on up are extremely radioactive. These elements have no stable isotopes.
Why are all actinides radioactive?
All of the actinides are radioactive, because their nuclei are so large that they are unstable and release great amounts of energy when they undergo spontaneous fission. Most of the actinides are not found in nature but are artificially produced in the laboratory.
Which family is made up of all radioactive elements?
actinide family
The actinide family is comprised of fifteen elements that start with actinium (Ac) at atomic number 89 and finish up with lawrencium (Lr) at number 103. It’s doubtful your teachers will ever ask you to remember all of the elements in the series.
Why is technetium promethium unstable?
The most stable neutron to proton ratio increases as atoms gain mass, changing from a 1:1 ratio for light elements to more like a 1.3:1 ratio for heavier elements. In the cases of technetium and the next lightest radioactive element (promethium), there is no combination of protons and neutrons that balances out.
Why is technetium so radioactive?
Technetium can only be produced artificially because most forms or isotopes of it (atoms of the same chemical element with different numbers of neutrons) have an excess of neutrons, making it very unstable.
What is the lightest radioactive element?
[en] Tritium is the lightest radioactive atom, an isotope of hydrogen.
Is technetium a radioactive?
Technetium (chemical symbol Tc) is a silver-gray, radioactive metal. It occurs naturally in very small amounts in the earth’s crust, but is primarily man-made. Technetium-99 is produced during nuclear reactor operation, and is a byproduct of nuclear weapons explosions.
Are lanthanides reactive?
The lanthanides are reactive, silver-colored metals. The most stable oxidation state for lanthanide atoms is +3, but the +2 and +4 oxidation states are also common. Although the lanthanides are sometimes called the rare earths, the elements are not particularly rare.
Why is samarium important?
One of the most important uses of samarium is in the manufacture of very powerful magnets. Samarium is combined with the metal cobalt to make samarium-cobalt, or SmCo, magnets. They are among the strongest magnets known. They also have other desirable properties.
Is gadolinium a metal?
A soft, silvery metal that reacts with oxygen and water. Gadolinium has useful properties in alloys. As little as 1% gadolinium can improve the workability of iron and chromium alloys, and their resistance to high temperatures and oxidation.
Why is gadolinium toxic?
Gadolinium is a rare earth metal that aligns with an MRI’s powerful magnetic field, but it is also toxic, so in its injectable form the metal is bound to chelating molecules to block its dangerous effects. Most of these molecules are then filtered through the kidneys and eliminated.
What are three interesting facts about gadolinium?
Here are some interesting facts about this metal:
- Gadolinium is silvery, malleable, ductile metal with a metallic sheen. …
- Gadolinium, like other rare earth elements, is not found in pure form in nature. …
- At low temperatures, gadolinium is more ferromagnetic than iron.
- Gadolinium has superconductive properties.