Isotopes
13 questions tagged Isotopes — spanning every one of the seven Ws.
Which element has the highest number of stable isotopes?
Tin has the most stable isotopes of any element, with 10 known stable isotopes. That is more than any other element on the periodic table.
Which element has the most isotopes overall?
Cesium is among the elements with the largest number of known isotopes, with more than 30 recorded isotopes. Many are radioactive and short-lived.
Which element has the longest half-life among radioactive elements commonly discussed?
Bismuth-209 has an extraordinarily long half-life of about 2 × 10^19 years, far longer than the age of the universe. It was once considered stable, but it is now known to be very weakly radioactive.
Whose discovery first showed that atomic mass can be measured in whole-number units with chlorine isotopes?
Francis Aston developed the mass spectrograph and discovered many isotopes in the 1910s and 1920s. His work helped explain why many elements have non-integer atomic masses.
How do isotopes of the same element differ?
Isotopes have the same number of protons but different numbers of neutrons. That means they are the same element chemically, but they can have different masses and stability.
What is isotopic abundance?
Isotopic abundance is the proportion of each isotope of an element found in a natural sample. It is why many atomic masses on the periodic table are not whole numbers.
Which element has the most isotopes?
Tin has the most stable isotopes of any element, with 10 naturally occurring stable isotopes.
Which element has the fewest stable isotopes?
Beryllium has only one stable isotope, beryllium-9.
How do isotopes differ from one another?
Isotopes are atoms of the same element with different numbers of neutrons. They have the same atomic number but different mass numbers.
Whose research first explained isotopes as atoms of the same element with different masses?
Francis Aston’s. In the 1910s, he used the mass spectrograph to show that many elements consist of isotopes.
How many isotopes does carbon have?
Carbon has several isotopes, but the best known are carbon-12, carbon-13, and carbon-14. Only carbon-12 and carbon-13 are stable.
How many isotopes of hydrogen are there?
Hydrogen has three main isotopes: protium, deuterium, and tritium. Only protium is stable in ordinary nature in any significant amount.
How many isotopes are there of uranium?
Uranium has many isotopes, but uranium-238 and uranium-235 are the most important. Uranium-238 is far more abundant in nature.