What experimental technique was used in the Geiger-Marsden experiment to detect particles?

The Geiger-Marsden experiment, also known as the Rutherford gold foil experiment, employed radiation counting as the primary technique to detect alpha particles. In this experiment, a radioactive source emitted alpha particles, which were directed at a very thin foil of gold. Surrounding the foil was a detection device that counted the alpha particles that were scattered at various angles after interacting with the gold atoms.

The key aspect of this method is that radiation counting allowed the researchers to quantify the number of alpha particles that were detected in different directions. This counting provided critical data regarding the deflection of alpha particles, leading to insights about the structure of the atom, including the existence of a dense nucleus. The results showed that most alpha particles passed through the foil with little to no deflection, while a small number were deflected at wide angles, indicating that the atom is mostly empty space with a concentrated positive charge at its center.

The other techniques, such as mass spectrometry, electrolysis, and X-ray diffraction, do not apply to the detection of alpha particles in this context. Mass spectrometry is used for separating ions based on mass, electrolysis involves chemical reactions driven by electric current, and X-ray diffraction is a technique used to study crystallography and material structures