Question

which observation led to discovery of neutron ?

Answer 1

Rutherford postulated the existence of some neutral particle having mass similar to proton but there was no direct experimental evidence. Several theories and experimental observations eventually led the discovery of neutron.

Answer 2

ANSWER

The discovery of neutrons can be traced back to the year 1930 when the German nuclear physicists Herbert Becker and Walther Bothe observed that a penetrating form of radiation was produced when the alpha particles emitted by polonium was incident on relatively light elements such as lithium, beryllium, and boron.

Hope It helps you