Which of the following elements is very stable?
Solution. (i) 18Ar and 2He are very stable elements, as their valance shells are completely filled. They belong to the group of inert or noble gases.
How do you know which element is more stable?
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.
Is lead the most stable element?
Some consider lead to be the most stable element of all because of its high atomic number. Lead has three stable isotopes and one unstable isotope. All of them are natural. The first isotope, Pb-204, is slightly radioactive and is considered primordial, meaning that it is older than the Earth itself.
Which is the most stable atom?
Nickel-62 is an isotope of nickel having 28 protons and 34 neutrons. It is a stable isotope, with the highest binding energy per nucleon of any known nuclide (8.7945 MeV).
What makes an atom stable?
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.
Why large nuclei are unstable?
By emitting alpha radiation or helium nuclei, an atom can transition from a high energy state to a lower energy state. This is why it is favored as a decay. The more protons the more repulsion and higher energy state. That’s why heavy nuclei become unstable.
What is meant by stable nuclei?
Nuclear stability means that nucleus is stable meaning that it does not spontaneously emit any kind of radiation. On the other hand, if the nucleus is unstable, it has the tendency of emitting some kind of radiation, which makes it radioactive.
How many stable nuclei are there?
Which radioisotope decays the fastest?