Question

A element is found in nature in two isotopic forms with mass numbers

Answer 1

Answer:

carbon

Explanation:

carbon has two isotopic forms I believe

Answer 2

Answer:

Oxygen and carbon etc

Explanation:

-:Oxygen isotops :-

Natural occurring oxygen has three isotope

O¹6. ,O¹7. ,O¹8

Out of this O¹6 is the most abundance

Atomic mass of O¹6-> 15.999 amu

Atomic mass of O¹7-> 16.899 amu

Atomic mass if O¹8-> 18.000 amu

-:Carbon isotops :-

There are natuarally 14 isotops of carbon O8-0²²

And out of this O¹² ans O¹³ is mostly stable isotops of carbon and O¹² is the most common one.