A molecule is defined as two or more atoms of the same element different element that are bound together. A molecule may be homonuclear, which means, it consists of atoms of one chemical element, as with oxygen (O2); or it may be heteronuclear, a chemical compound composed of more than one element, as with water (H2O).
An isotope is the vary of neutrons in an element, causing its atomic mass to change. While an ion is a charged atom that bonds to be stable.
no it is not possible, because they both have the same number of valence electrons in each element. in a compound you are supposed to have two or more elements that have different numbers of valence electrons so when put together they for a compound.