Elements that are stable

Answer 1

Those elements which have completely filled or exactly half filled electron in their outermost shells are stable but the copletely filled are more stable like : He, Ne, Xe etc all the elements of gr 8

Answer 2

• The noble gases {Helium, He; Neon, Ne; Argon, Ar; Krypton, Kr; Xenon, Xe; Radon, Rn} are stable elements.

They have a special stability because they have the outermost s and p sublevels (the last two s and p sublevels) completely filled with an octet(8) of electrons. Because the s sublevels are filled with 2 electrons and the p sublevels are filled with 6 electrons. (2+6 = 8)

• Ions with a noble-gas notation acquire the Noble Gases special stability, too.

Example:

Fluorine, F, has this electron-configuration notation: 1s22s22p5

In electron-configuration notation the numbers in superscript are the number of electrons. The letters (s, p, d, l) are the sublevels. And the numbers (1,2,3,4,5,6,7) are the energy levels.

According to the electron-configuration shown above, Fluorine doesn't have an octet of electrons because 2+5 = 7. It needs one electron to have an octet of electrons!!

Now, if Fluorine gains one electron, becoming a negative ion (F-), it acquires a noble gas stability. 1s22s22p5+1 =1s22s22p6

Ion, is an atom that has gained or lost electrons, and now has a

negative or positive charge, respectively.

Answer 3

If stable means it won't decay, all non-radioactive elements are stable; if it means it won't react with other elements, only noble gases are stable.

Answer 4

Elements with an atomic number under 83 (excepting Pm and Tc) are considered stable; but more exactly many elements considered as stable have some isotopes radioactive.

Answer 5

Elements with all 8 valence electrons.

Answer 6

Over one million.

Answer 7

neon has 8 veilence electrons