.In the early 1900s, two associates of New Zealander Ernest Rutherford bombarded thin sheets of gold with positively charged subatomic particles.
They found that most of the particles passed right through the sheets but some bounced back as if they had hit something solid. Based on their results what do you think the majority of an atom is made of? What part of the atom caused the particles to bounce back?
The experiment revealed that particles that bounced backwards had hit dense, positively charged, nuclei, where most of the mass atoms resides. Negatively charged electrons fill the large gaps in between atomic nuclei.
The Rutherford experiment is one of the most important in the history of science. Nothing was known about the structure of an atom before that.
Based on the results of the experiment you described, the majority of an atom is made of empty space. This is because most of the positively charged subatomic particles passed right through the thin sheets of gold, indicating that there was very little resistance or obstruction in their path.
However, some particles did bounce back, suggesting that there was something solid within the atom that caused this interaction. The part of the atom that caused the particles to bounce back is the nucleus. The nucleus is a small, dense, and positively charged region at the center of an atom. It contains most of the atom's mass and is made up of protons and neutrons. In this experiment, the positively charged subatomic particles must have come close enough to the nucleus to experience the repulsive force from the positively charged protons, causing them to deflect or bounce back.
The discovery of the nucleus and the experiment you mentioned played a significant role in shaping our understanding of the structure of atoms and the nature of matter. Ernest Rutherford's experiment is known as the gold foil experiment or Rutherford's scattering experiment.