'Asotopes' ?????
I think you mean 'ISOTOPES'. Note the spelling.
An isotope is an atom of an element with a different number of neutrons. e.g.
Hydrogen
#1 protium ; 1 proton, 0 neutrons and one electrons (commonest form)
#2 deuterium ; 1 proton, 1 neutron and one electrons ( heavy hydrogen)
#3 tritium ' 1 proton, 2 neutrons and one electrons (super heavy hydrogen ; radio active)
These are the three isotopes of hydrogen.
Do Not confuse with ALLOTROPES. a different physical form of the same element e.g. Diamond and Graphite two of the allotropes of CARBON.
Many other elements exhibit both isotopes and allotropes.