J.J. Thomson while performing an experiment noticed the canal rays and said that they were electrically negative in nature and that was due to negatively charged particles. He called these negatively charged particles electrons.
Since, at that time many speculations were being done regarding the structure of an atom, he provided his model of an atom which is commonly called the "Plum-pudding model or Watermelon model".
Since, the atoms were electrically neutral, therefore he said that the electrons were uniformly distributed in a positively charged shell just like there are seeds in a watermelon.
But his speculations and model were rejected after Rutherford's 'Gold foil Experiment'.
J. J. Thomson's experiments provided evidence for the existence of electrons as subatomic particles within the atom. This led to the plum pudding model of the atom, where electrons were embedded in a positively charged "pudding." These experiments laid the foundation for our understanding of atomic structure.
John Dalton, J.J. Thomson, Ernest Rutherford, Niels Bohr, and Erwin Schrödinger were all instrumental in the development of our understanding of the atom. Each of them made significant contributions to the atomic theory and the structure of the atom.
Thomson hadn't an instrument; this model is only a hypothesis.
J.J. Thomson proposed the existence of small negatively charged particles inside an atom, which he called electrons. This discovery was a crucial development in understanding the structure of atoms and led to the plum pudding model of the atom.
Joseph J. Thomson's postulates included the idea that electrons are negatively charged particles, they have a much smaller mass compared to atoms, and they are uniformly distributed within the atom. These postulates were part of Thomson's plum pudding model of the atom.
J.J. Thomson provided evidence about the structure of an atom through his discovery of the electron using cathode ray tubes. His experiments showed that electrons are negatively charged particles and are present in all atoms, leading to the development of the plum pudding model of the atom.
It was J. J. Thomson (Joseph John Thomson)
J. J. Thomson's experiments provided evidence for the existence of electrons as subatomic particles within the atom. This led to the plum pudding model of the atom, where electrons were embedded in a positively charged "pudding." These experiments laid the foundation for our understanding of atomic structure.
The evidence for JJ Thomson was that the plum pudding model could not predict why atoms absorbed and emitted spectral lines.
Thomson is responsible for discovering that an atom contains electrons.
Scientists know about the structure of an atom through experimentation, such as using techniques like X-ray crystallography and spectroscopy to study the behavior of atoms. Theories like quantum mechanics also provide a framework for understanding the atom's structure based on experimental evidence.
The evidence for JJ Thomson was that the plum pudding model could not predict why atoms absorbed and emitted spectral lines.
Thomson had two pieces of evidence: 1- No matter what metal he used for the disk, the particles produced were indentical. 2- The particles had about 1/2000 the mass of a hydrogen, the lightest atom. These experiments provided the first evidence that atoms are made of even smaller particles.
a cathode ray
J.J. Thomson discovered the electron and proposed the plum-pudding model for the atom.
Neil Bohr
The plum pudding model by JJ Thomson.