The question asks about the discovery of the electron and the experimental setup used. This is a fundamental concept in atomic structure from chemistry and physics. We need to recall which scientist is credited with the discovery of the electron and the associated experiment.
Correct Option: A) J.J. Thomson is credited with the discovery of the electron using the cathode ray discharge tube experiment.
This question tests the fundamental properties of cathode rays and their interaction with electric fields. Cathode rays are streams of electrons, which are negatively charged particles. The behavior of charged particles in an electric field is governed by the principle that opposite charges attract and like charges repel.
Correct Option: B) The positively charged plate
The question asks for the standard symbol used to represent the charge on an electron. This is a fundamental concept in chemistry and physics, related to the basic particles that make up an atom.
Correct Option: D) eā»
The symbol 'eā»' is universally used in chemistry and physics to denote an electron, with the superscript minus sign indicating its negative charge.
The question asks about the fundamental particle discovered through cathode ray discharge tube experiments. We need to recall the historical experiments related to atomic structure and identify which particle was discovered using this specific setup.
A) Electron ā J.J. Thomson's cathode ray experiments definitively led to the discovery of the electron, a negatively charged fundamental particle of an atom.
The question asks to identify the scientist who first observed canal rays (anode rays), which eventually led to the discovery of the proton. This is a direct recall question from the history of atomic structure and fundamental particle discoveries.
Correct Option: C) E. Goldstein. E. Goldstein was the first to observe canal rays (anode rays) in 1886, which were later understood to be streams of positive ions and played a crucial role in the discovery of the proton.
The question asks about the nature of canal rays obtained in a discharge tube. This refers to a historical experiment that led to the discovery of protons. Understanding the setup and observations of this experiment is key to determining the charge of these rays.
D) Positively charged ā Canal rays are streams of positively charged ions, formed when electrons from cathode rays ionize the residual gas atoms in the discharge tube. These positive ions are then accelerated towards the perforated cathode.