Yes. It accounts for around 11% of the barium of earth.
The isotope symbol for Barium-137 is Ba-137.
Not in elemental form: it is too reactive.
Barium is a natural element. However, because it is so highly reactive, it does not occur naturally in a pure form.
Barium 137 has 56 protons and 56 electrons.
The element with an atomic number of 56 is barium (Ba). However, the mass number of 137 amu does not match any known isotopes of barium. This suggests that the atom in question may be an isotope of barium that is not naturally occurring or may have been produced in a laboratory setting.
Barium has seven isotopes, with atomic masses ranging from 130 to 138. The most abundant isotope of barium is Barium-138, making up about 71% of naturally occurring barium. Barium-137 is a radioactive isotope with a half-life of about 2.5 minutes.
Can be used in Fluoirescent tubes and also make Paint, Bricks, Tiles, Glass and Rubber.
Same mass, atomic number one lower - Cs - caesium
Cesium-137
The atomic number of barium is 56. It has naturally occurring isotopes with mass numbers of 130, 132, 134, 135, 136, 137, and 138.
Barium 137 has 56 protons and 56 electrons.
Iodine 131 has a half-life of 8.0197 days. Barium has no half-life. So no, Iodine-131 is not more stable than barium-137.