Electrons

Definition

Electrons are subatomic particles that carry a negative electric charge and are found in all atoms. They play a crucial role in various physical phenomena, including Coulomb's law, electrical current, the motion of charged particles in magnetic fields, and the Hall effect.

5 Must Know Facts For Your Next Test

1. Electrons are responsible for the attractive and repulsive forces described by Coulomb's law, which governs the interaction between charged particles.
2. The flow of electrons through a conductor is the basis of electrical current, as described in Ohm's law and the study of electrical circuits.
3. The motion of charged particles, such as electrons, in a magnetic field is the foundation for understanding the behavior of charged particles in a magnetic field.
4. The Hall effect, which occurs when a current-carrying conductor is placed in a magnetic field, is a result of the deflection of electrons due to the magnetic force acting on them.
5. Electrons can be either free, as in a conductive material, or bound to atoms, as in an insulating material, which affects their behavior in electrical and magnetic phenomena.

Review Questions

• Explain how the properties of electrons, such as their charge and mass, contribute to Coulomb's law and the interaction between charged particles.
  • Electrons have a negative electric charge, which means they exert a repulsive force on other negatively charged particles and an attractive force on positively charged particles, as described by Coulomb's law. The magnitude of this force is directly proportional to the charges of the particles and inversely proportional to the square of the distance between them. Additionally, the mass of electrons, although small, plays a role in the inertia of charged particles and their response to electric and magnetic fields.
• Describe the role of electrons in the flow of electrical current and how this relates to the study of electrical circuits.
  • Electrical current is the flow of electrons through a conductive material, such as a metal wire. The movement of these charged particles is the basis for understanding electrical circuits and the behavior of various electrical components, such as resistors, capacitors, and inductors. The properties of electrons, including their charge and mobility, determine the resistance, voltage, and current in a circuit, as described by Ohm's law and other fundamental principles of electricity.
• Analyze the motion of electrons in a magnetic field and explain how this phenomenon is related to the Hall effect.
  • When a charged particle, such as an electron, moves through a magnetic field, it experiences a force perpendicular to both the direction of the magnetic field and the direction of the particle's motion. This force, known as the Lorentz force, causes the charged particle to follow a curved path. In the Hall effect, a current-carrying conductor is placed in a magnetic field, and the deflection of the electrons due to the Lorentz force results in the buildup of charge on the sides of the conductor, creating a potential difference that can be measured. This Hall voltage is directly related to the properties of the electrons, the strength of the magnetic field, and the current flowing through the conductor.

Related terms

Protons:

Positively charged subatomic particles that, along with neutrons, make up the nucleus of an atom.

Charge:

A fundamental property of matter that can be either positive or negative, and is the source of electrical and magnetic phenomena.

Electric Field: The region surrounding a charged particle or object where a force would be exerted on another charged particle.