Francium has no stable isotopes. That means it doesn't really have a "most abundant" isotope; they're all pretty much nonexistent. There are trace amounts of 223Fr in uranium minerals, because it's a decay product of 227Ac (which is itself a decay product in the decay chain of uranium).
The francium's most abundant isotope is francium-223.
Tritium is the most abundant hydrogen isotope
Arsenic has only one stable isotope 75As
There is only one abundant isotope of fluorine and that is 19FFluorine-19 is the most common isotope, its abundance is classed as 100% because no other Fluorine isotopes exist in significant quantities. It is also the only stable Fluorine isotope.
Chlorine-35 is the most abundant isotope of chlorine.
Potassium I reckon
An isotope of cobalt is used to to kill cancer cells. The isotope americium-241 is used in smoke detectors.
No. All atoms, except the most abundant isotope of hydrogen, can be divided into the subatomic particles protons, neutrons, and electrons. The most abundant hydrogen isotope does not have neutrons.
As the atomic number of nitrogen is 7, the most abundant isotope of this atmospheric gas must have 7 neutrons (14.007 - 7 = about 7), and this will make nitrogen-14 that isotope that is most abundant.
The isotope with a mass of 32 amu is the most abundant. This can be determined by comparing the atomic mass of sulfur (32.06 amu) to the masses of the isotopes. Since the atomic mass is closest to 32 amu, this isotope is the most abundant.
Can't tell because it is NOT true
The most abundant isotope has 7 each.
Antimony-121 at 57.25%, the rest is Antimony-123