Question

A proton is made of 2 up quarks and a down quark (uud). Calculate its charge.

Short answer

Answer: The charge of a proton is +1 elementary charge.

Step-by-step solution

Identify the charges of each quark

The charges of the quarks are: - Up quark (u): +2/3 elementary charge - Down quark (d): -1/3 elementary charge

Add the charges of the quarks in a proton

A proton has 2 up quarks (u) and 1 down quark (d). The total charge of a proton can be calculated as follows: Total charge = (Charge of up quark) * 2 + (Charge of down quark) * 1

Calculate the total charge of the proton

Total charge = (2/3) * 2 + (-1/3) * 1 = 4/3 - 1/3 = 3/3 = 1 elementary charge The charge of the proton is +1 elementary charge.

Key concepts

Understanding Quarks

Quarks are fundamental particles and essential building blocks in the universe. They are a type of elementary particle, akin to the components of everything you see around you. In physics, quarks are unique because they combine to form composite particles, usually baryons like protons and neutrons. A quark can come in different 'flavors,' such as 'up,' 'down,' 'charm,' 'strange,' 'top,' and 'bottom.'

Importantly, quarks possess a fractional charge measured in units of the elementary charge, which is the basic unit of electric charge. For example:

• Up quarks have a charge of \( +\frac{2}{3} \)
• Down quarks have a charge of \( -\frac{1}{3} \)

These minimum charges set quarks apart from particles like electrons, which have a full negative charge. Understanding how these charges add or subtract is crucial for grasping how more complex structures form. In the case of protons, knowing the charges of quarks is the first step to determining their total charge.

Proton Composition and Charge

Protons are a type of baryon found in atomic nuclei. They are composed of three quarks held together by the strong nuclear force. Specifically, each proton consists of two up quarks and one down quark, notated as 'uud.' This composition gives the proton its characteristic properties, including its electric charge.

To calculate the charge of a proton, remember that it houses:

• 2 up quarks, each with a charge of \(+\frac{2}{3}\)
• 1 down quark, with a charge of \(-\frac{1}{3}\)

Summing these, the total charge of a proton is calculated as:\[Total\ charge = (2 \times \frac{2}{3}) + (1 \times -\frac{1}{3}) = \frac{4}{3} - \frac{1}{3} = \frac{3}{3} = 1\]Thus, the overall charge of a proton is equal to one elementary charge, which is positive. This charge contributes significantly to the electric properties of atoms, making protons a crucial part of atomic structure.

Elementary Charge and Its Importance

The elementary charge is a fundamental physical constant denoting the smallest unit of electric charge that is possible in nature. Symbolized as \( e \), this charge is approximately equal to \( 1.602 \times 10^{-19} \) coulombs. In particle physics, this represents the charge carried by a proton, and the opposite of the charge carried by an electron.

• Protons have a charge of \(+e\)
• Electrons have a charge of \(-e\)

Because it sets the scale for charge at the quantum level, the elementary charge plays a vital role in the laws and interactions that govern the universe. It allows scientists to express the charges of particles like quarks in simple fractional terms using multiples of this basic unit.

Thus, when we describe the charge of a proton as \(+1\) elementary charge, we are referencing this universal standard. Understanding the elementary charge helps not only in comprehending atomic and sub-atomic phenomena but also in broad fields such as electromagnetism and chemistry, where the concept of charge influences many fundamental processes.