Question

an element can have atom with different mass number but same chemical properties and same are also used in the field of medicine. in the. treatment of disease. science class 9

Answer 1

carbon and nitrogen and oxygen

Answer 2

isotopes is referred to as the atoms of the same element having the same atomic number but different atomic mass
the isotopes of some elements are used in the treatment of various diseases like
an isotope of iodine is used in the treatment of go it re
an isotope of cobalt is used in the treatment of cancer