isotopes, atoms having same atomic number



Isotopes were first discovered by Soddy in radioactive elements while isotopes of nonradioactive elements were discovered by  Richard.

Isotopes means same position ( iso :same : topes : position )

“Atoms of same element having same atomic number but mass number is different, are called isotopes.”

Ex.      (i)        17Cl3517Cl37

(ii)       8O168O17, 8O18

(iii)     7N13, 7N14, 7N15

(iv)      1H1, 1H2, 1H3