Question

An element can have atoms with different mass numbers but same chemical properties and some are also used in the field of medicine in the treatment of diseases.

-What are such element known as?
-define such elements and also write one example?
-give their one point of difference from isobars?

Answer 1

These are called isotopes
These elements contain different numbers of neutrons, which causes the mass changes.
Carbon-12, Carbon-13, Carbon-14
Isobars are elements that have the same mass number but different proton numbers, which is their main difference.