Question

How do we interpret the subscripts for the full symbols of an electron and a positron?

Short answer

The subscripts for the full symbols of an electron (\(e^-\)) and a positron (\(e^+\)) represent their respective electric charges. The electron has a negative charge, while the positron has a positive charge. Both charges have a magnitude equal to the elementary charge, approximately \(\pm 1.6 \times 10^{-19}\) Coulombs.

Step-by-step solution

Identify the full symbols of an electron and a positron

In particle physics, an electron is represented by the symbol \(e^-\) and a positron is represented by the symbol \(e^+\). Here, we are asked to interpret the subscripts for these full symbols.

Understand what subscripts represent in the context of particle physics

In particle physics, subscripts usually denote the charge of the particle, its spin, or other quantum numbers. In this case, the subscripts for the electron and positron symbols: \(e^-\) and \(e^+\), represent their respective electric charges.

Interpret the subscript for the electron

For the electron symbol, \(e^-\), the subscript is the negative sign. This indicates that the electron has a negative charge. The magnitude of this charge is equal to the elementary charge, approximately \(-1.6 \times 10^{-19}\) Coulombs.

Interpret the subscript for the positron

For the positron symbol, \(e^+\), the subscript is the positive sign. This indicates that the positron has a positive charge. The magnitude of this charge is also equal to the elementary charge, approximately \(1.6 \times 10^{-19}\) Coulombs. In conclusion, the subscripts for the full symbols of an electron and a positron represent their respective electrical charges. The electron has a negative charge, and the positron has a positive charge, both having a magnitude equal to the elementary charge.

Key concepts

Electron

An electron is one of the fundamental particles in the realm of particle physics. Electrons belong to a category of particles known as leptons, and they are stable, meaning they do not naturally decay into other particles on their own. Electrons carry a negative electric charge, which is crucial in various physical phenomena, including electricity and magnetism.

The symbol for an electron is typically written as \( e^- \). The negative sign in this symbol reflects its negative charge. Electrons are incredibly small, with a mass of approximately 9.11 x 10^{-31} kilograms, which is over 1800 times lighter than a proton or a neutron in an atom.

• Electrons orbit the nucleus of an atom.
• They play a key role in chemical reactions.
• Electrons contribute to electrical conductivity.

Positron

A positron is the antimatter counterpart of an electron. While electrons carry a negative charge, positrons carry a positive charge. This is why the symbol for a positron is written as \( e^+ \). In particle physics, the existence of antimatter was a ground-breaking discovery as it extends our understanding of the universe.

Positrons have the same mass as electrons, making them equally light-weight. They are typically generated in certain types of radioactive decay, known as beta plus decay, and in interactions involving high-energy photons.

• Positrons participate in collisions with electrons, known as annihilation.
• They are important in medical imaging technology, such as PET scans.
• Studying positrons helps physicists test fundamental theories of physics.

Electric Charge

Electric charge is a fundamental property of particles such as electrons and positrons. It determines how particles interact with each other and with electric and magnetic fields. Particles with opposite charges—one positive and one negative—attract each other, while particles with like charges repel each other.

The concept of electric charge was first introduced to describe the forces that result in electricity and magnetism. It is a conserved quantity, meaning that the total electric charge in an isolated system remains constant over time.

• Electric charge comes in two types: positive and negative.
• Units of electric charge are measured in Coulombs (C).
• Charge conservation is fundamental in all physical processes.

Elementary Charge

The elementary charge is often denoted by the symbol \( e \) and represents the smallest unit of electric charge that is individually observed in nature. It forms a foundational aspect of particle physics, as it determines the magnitude of charge carried by particles like electrons and positrons.

The magnitude of the elementary charge is approximately \( 1.6 imes 10^{-19} \) Coulombs. It is the charge of a single proton or positron, while an electron, which has a negative charge, holds a charge of approximately \( -1.6 imes 10^{-19} \) Coulombs.

• The concept of elementary charge is integral to understanding atomic structures.
• It provides a unit of measurement for quantifying electric charge.
• Understanding elementary charge helps in explaining how atoms bond together.