At least 10 ...

 

Thank you.

umm, there are none. an atom of any lement that was synthesised in a lab and an atom of the same type that was picked up off the ground would be indistinguishable.

i didn't mean that,

man made elements like technicium...nd natural elements like hYdrogen or something..

 

Thank You

Well, the man made ones are horribly expensive and they are radioactive (but so are some natural elements).

Man made ones haven't been found in nature yet.... we bangem out in reactors and accelerators, that's about it isn't it?

well, you could go into te chemical properties but theres the same differences between 2 natural elements.

At least 10 ...

 

Thank you.

 

Sounds like homework to me. And a job for Google and a periodic table. Have at it!