Question

In Wilson cloud chamber experiment, two particles were found to show equal deviations but in opposite directions. The names positron and negatron were given to these particles by Anderson. Hence, Negatron is (a) neutron (b) neutrino (c) proton (d) electron

Short answer

Negatron is (d) electron.

Step-by-step solution

Understanding the Context

The Wilson cloud chamber experiment was a pioneering effort in the discovery of new particles in physics. It's known for revealing the tracks of charged particles through the condensation of vapor. If two particles show equal deviations in opposite directions, it suggests they have charges of equal magnitude but opposite signs. The term 'negatron' was coined by Carl David Anderson for what is commonly known as an electron. A positron is the antimatter counterpart of the electron, having the same mass but opposite charge.

Determining the Charge and Mass

Given that the negatron and positron show equal but opposite deviations, we deduce that they have equal mass and opposite charges. The particle names already suggest their charges: 'positron' indicating a positive charge and 'negatron' indicating a negative charge.

Matching Particle Name to Identity

By matching the properties of the particles from the experiment to the list of given particles, we can identify that a neutron is neutral and would not deviate in a magnetic field. A neutrino is also neutral and incredibly light, not fitting the characteristics. A proton has a positive charge and is significantly heavier. Thus, an electron with a negative charge and similar mass to the positron is the most accurate match for the negatron.

Key concepts

Physical Chemistry

Physical Chemistry is a branch of chemistry that deals with the study of how matter behaves on a molecular and atomic level and how chemical reactions occur. It involves concepts of both physics and chemistry to understand the physical properties of molecules, the forces that act upon them, and the way they react. An essential tool for visualizing the behavior of charged particles, like in the Wilson cloud chamber experiment, is a prime example of the application of physical chemistry.

At its core, physical chemistry looks at these reactions through the laws of physics. The Wilson cloud chamber, by showing the tracks of charged particles, offers insight into the atomic world, allowing scientists to deduce properties like charge and mass from the way particles interact with their environment. This combination of chemistry and physics is crucial not only for discovering new particles but also for developing new technologies, medicines, and materials.

Charged Particles

Charged particles are integral to our understanding of particle physics and physical chemistry. They are atoms or molecules that carry a net electric charge, either positive or negative. In the context of the Wilson cloud chamber experiment, the movement of such particles under the influence of a magnetic field allows scientists to observe their behavior and properties.

Moreover, charged particles leave a distinct trail as they move through a supersaturated vapor in a cloud chamber. When these particles collide with the gas molecules, tiny droplets form along their paths, making them visible to the observer. This phenomenological view lets scientists infer not just the presence of charged particles, but also their speed, direction of travel, and the magnitude of their charge. Such discernibility is key to the identification of particles like the negatron, which is actually an electron with a negative charge.

Particle Physics

Particle physics is the field of physics that studies the nature of particles that are the constituents of what is usually referred to as matter or radiation. In particle physics, one tries to understand the smallest known building blocks of the universe and the interactions that govern their dynamics. The Wilson cloud chamber is a tool in experimental particle physics that was historically significant for the detection and identification of charged subatomic particles like the negatron and the positron.

In these experiments, every observed track indicates the passage of a particle whose properties—such as mass, charge, and energy—can be analyzed. These observations contribute to our overall understanding of the universe at the smallest scales. The identification of the positron and the negatron not only validated the existence of antiparticles but also provided substantial evidence for theoretical predictions in quantum mechanics and electromagnetic theory.