Question

why isotopes are written as identical chemical properties

Answer 1

coz they are having same atomic number and chemical properties are determined on the basis of atomic no. nt mass

Answer 2

isotopes have similar chemical properties because isotopes of an element have the same number of electrons as an atom of that element. The electron arrangement is the same owing to same chemical properties. However they have different numbers of neutrons, which affects the mass number. Mass number determines the physical properties such as boiling/melting/density etc.