What does stable mean in radioactivity?
An atom is stable if the forces among the particles that makeup the nucleus are balanced. An atom is unstable (radioactive) if these forces are unbalanced; if the nucleus has an excess of internal energy. Instability of an atom’s nucleus may result from an excess of either neutrons or protons.
How do you know if a nuclide is stable?
Unstable or Stable Calculate the total number of nucleons (protons and neutrons) in the nuclide. If the number of nucleons is even, there is a good chance it is stable.
Why are some nuclides stable and other unstable?
The stability of a particular nuclide depends on the composition of its nucleus, including the number of protons, the number of neutrons, and the proton-to-neutron ratio. In nuclear reactions, it is the nucleus of the atom that gains stability by undergoing a change of some kind.
What is the difference between a stable and unstable isotope?
Stable isotopes are naturally occurring forms of elements that are non-radioactive. Unstable isotopes are atoms having unstable nuclei. Therefore, these elements undergo radioactivity. This is the main difference between stable and unstable isotopes.
What makes an element stable?
A stable atom has a net charge of 0. In other words, it has an equal number of protons and electrons. The positive protons cancel out the negative electrons. When the number of electrons does not equal the number of protons, the atom is ionized.
Which element has no stable nuclides?
Of the known chemical elements, 80 elements have at least one stable nuclide. These comprise the first 82 elements from hydrogen to lead, with the two exceptions, technetium (element 43) and promethium (element 61), that do not have any stable nuclides.
What is the most stable nucleus?
Iron-56 which is the most popular isotope of iron is considered as the most stable nucleus mainly because it has the lowest mass per nucleon of all nuclides. Further, with a binding energy of 8.8 MeV per nucleon, iron-56 is a tightly and efficiently bound nucleus.
What is stable and unstable nuclides?
Elements are considered to be “naturally occurring” when they can be found in nature as stable or unstable nuclides. Unstable nuclides could be created by bombarding stable nuclides with neutrons of other particles in particles accelerators and are called artificial elements.
How many stable nuclides are there?
252
Most naturally occurring nuclides are stable (about 252; see list at the end of this article), and about 34 more (total of 286) are known to be radioactive with sufficiently long half-lives (also known) to occur primordially.
What is meant by a stable isotope?
Stable isotopes are non-radioactive forms of atoms. Although they do not emit radiation, their unique properties enable them to be used in a broad variety of applications, including water and soil management, environmental studies, nutrition assessment studies and forensics.
What gives stability to an atom?
Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons. Sodium atoms have 11 electrons. Two of these are in the lowest energy level, eight are in the second energy level and then one electron is in the third energy level.
What is an unstable nuclide?
All unstable elements are radioactive contain large numbers of protons or higher or lower number of neutrons required for the nuclear stability. Any elements could have unstable nuclides and depends on the number of neutrons it has.