<P> Of the 94 naturally occurring elements , 83 are considered primordial and either stable or weakly radioactive . The remaining 11 naturally occurring elements possess half lives too short for them to have been present at the beginning of the Solar System , and are therefore considered transient elements . Of these 11 transient elements , 5 ( polonium , radon , radium , actinium , and protactinium ) are relatively common decay products of thorium and uranium . The remaining 6 transient elements ( technetium , promethium , astatine , francium , neptunium , and plutonium ) occur only rarely , as products of rare decay modes or nuclear reaction processes involving uranium or other heavy elements . </P>
<P> Of the 94 naturally occurring elements , 83 are considered primordial and either stable or weakly radioactive . The remaining 11 naturally occurring elements possess half lives too short for them to have been present at the beginning of the Solar System , and are therefore considered transient elements . Of these 11 transient elements , 5 ( polonium , radon , radium , actinium , and protactinium ) are relatively common decay products of thorium and uranium . The remaining 6 transient elements ( technetium , promethium , astatine , francium , neptunium , and plutonium ) occur only rarely , as products of rare decay modes or nuclear reaction processes involving uranium or other heavy elements . </P>
an element or compound which occurs naturally in the earth is a ( n )
an element or compound which occurs naturally in the earth is a ( n )
primordial
primordial