- #1
ascendant
- 9
- 0
How do we know protons, neutrons and electrons exist? And what exactly is a positive or negative charge?... meaning what is it that makes it positive or negative.
ascendant said:I basically mean what is a charge? what is it about the object that gives off this thing that we call charge.
Protons were first discovered by Ernest Rutherford in 1917 through his gold foil experiment. He observed that some alpha particles were deflected at large angles, indicating the presence of a dense, positively charged particle in the atom's nucleus. Later experiments, such as the discovery of isotopes and the development of particle accelerators, further confirmed the existence of protons.
Neutrons were first hypothesized by James Chadwick in 1932 to explain the discrepancy between the atomic mass and atomic number of elements. His experiments with beryllium and alpha particles led to the discovery of neutrons, which have no charge but contribute to the atomic mass of an atom. Subsequent experiments, such as neutron scattering, have further confirmed the existence of neutrons.
Electrons were first discovered by J.J. Thomson in 1897 through his cathode ray experiment. He observed that a beam of particles with a negative charge was produced when an electric current was passed through a vacuum tube. Later experiments, such as the photoelectric effect and the double-slit experiment, have further confirmed the existence of electrons and their wave-particle duality.
The properties of protons, neutrons, and electrons have been studied extensively through various experiments, such as spectroscopy, scattering experiments, and particle accelerators. Scientists have determined their masses, charges, and other characteristics through these experiments, providing a deeper understanding of the fundamental building blocks of matter.
The discovery of protons, neutrons, and electrons provided evidence for the existence of atoms, which were first proposed by Greek philosophers in ancient times. Later experiments, such as the development of the periodic table and the discovery of isotopes, further confirmed that atoms are composed of protons, neutrons, and electrons. The understanding of atomic structure and behavior has been continually refined through advancements in technology and scientific research.