Unstable isotopes can be chemically reactive.
Isotopes differ each other from the number of neutrons which is a chemically inert subatomic particle.
Unstable isotopes are radioactive isotopes, can disintegrate and emit radiations.
yes argon is chemically inert because its valence shell is complete.
Helium is considered an inert noble gas. Only some unstable compunds of helium are known today: HeNe, HgHe10, WHe2.
Hydrogen has 1 unstable isotope, and 2 stable isotopes.
Unstable isotopes can spontaneously undergo changes, transforming them into other isotopes of the same or of different elements. Stable isotopes do not. Some isotopes are very unstable and exist for less than a second; others can exist for billions of years but still be unstable. Many elements consist of more than one isotope. One or more of these isotopes may be unstable. In isotopes of an element, the nucleus contains different numbers of neutrons while the number of protons remains the same and determines how the atom behaves chemically. There are several types of instability (too few neutrons, too many neutrons) and several types of decay.
Covalent Bond. Chemically Active. The only elements that are inert are group 18, or 8A.
Not all isotopes are unstable. But now more than 3 000 unstable isotopes are known, artificial or natural.
Noble gases are chemically inert. They have completely filled orbitals, hence are generally non-reactive (or chemically inert).
inert
no
Gold is active, or at least not inert. Only the noble gases are inert.