Carga elétrica

Summary

The video explains the concept of electric charge through the atomic model, focusing on Rutherford's atomic structure. It details the nucleus, composed of protons and neutrons, and the electron cloud. The video explores the interaction of particles (protons, neutrons, and electrons) with magnetic fields, highlighting how only protons and electrons are affected due to their electric charges. The discussion also covers the calculation of net charge in various scenarios where the number of protons and electrons differ, and introduces the formula to calculate charge based on excess or lack of electrons, along with units like coulomb, microcoulomb, and nanocoulomb.

Takeaways

• 😀 The atom consists of two main regions: the nucleus (containing protons and neutrons) and the electron cloud (where electrons are found).
• 😀 Protons and neutrons are made up of smaller particles called quarks, while electrons are not divisible and have not yet been found to consist of smaller particles.
• 😀 Electric charge is a property that allows particles to interact with magnetic fields. This interaction causes deviations for charged particles (like protons and electrons) but not for neutral particles (like neutrons).
• 😀 The charge of a proton is +1.6 × 10^-19 Coulombs, and the charge of an electron is the same magnitude but negative.
• 😀 When a body has an equal number of protons and electrons, it is electrically neutral, and the total charge is zero.
• 😀 If a body has more protons than electrons, it is positively charged, and the excess charge can be calculated by multiplying the number of excess protons by the charge of a single proton.
• 😀 Conversely, when a body has more electrons than protons, it is negatively charged, and the excess charge can be calculated by multiplying the number of excess electrons by the charge of a single electron.
• 😀 The equation to calculate charge is q = n × e, where q is the total charge, n is the number of excess or missing electrons, and e is the elementary charge (1.6 × 10^-19 Coulombs).
• 😀 Charge measurements are commonly in sub-multiples of Coulombs, such as microCoulombs (10^-6 C), nanoCoulombs (10^-9 C), or picoCoulombs (10^-12 C).
• 😀 The process of charging a body can occur through different methods such as friction, contact, or induction, affecting the number of protons or electrons and the resulting charge.

Q & A

What is Rutherford's atomic model?

Rutherford's atomic model suggests that the atom consists of two distinct regions: the dense and central nucleus, which contains protons and neutrons, and the outer region called the electrosphere, which contains electrons.

What are the characteristics of protons, neutrons, and electrons?

Protons are positively charged, neutrons have no charge, and electrons are negatively charged. Protons and neutrons are composed of quarks, whereas electrons are fundamental particles that are not composed of smaller components.

Why do only protons and electrons interact with magnetic fields?

Only protons and electrons have an electric charge, which allows them to interact with magnetic fields. Neutrons, having no charge, do not experience any deflection in a magnetic field.

What is the charge of an electron?

The charge of an electron is -1.6 × 10^-19 Coulombs (C), a value that is equal in magnitude but opposite in sign to the charge of a proton.

How can the electric charge of a body be calculated?

The total electric charge of a body can be calculated by multiplying the excess or missing number of electrons (or protons) by the elementary charge (1.6 × 10^-19 C). The formula is Q = n × e, where Q is the total charge, n is the number of excess or missing particles, and e is the elementary charge.

What does it mean for a body to be electrically neutral?

A body is electrically neutral when the number of protons equals the number of electrons, resulting in no net charge.

What happens when a body has more protons than electrons?

When a body has more protons than electrons, it is positively charged, and the excess positive charge can be calculated by multiplying the number of excess protons by the charge of a proton (1.6 × 10^-19 C).

What is the electric charge of a body that has more electrons than protons?

A body that has more electrons than protons is negatively charged. The excess negative charge can be calculated by multiplying the number of excess electrons by the charge of an electron (-1.6 × 10^-19 C).

How is the charge calculated when a body gains extra electrons?

If a body gains extra electrons, it becomes negatively charged. The charge can be calculated by multiplying the number of extra electrons by the elementary charge (1.6 × 10^-19 C) and assigning a negative sign to the result.

What are the common submultiples of a Coulomb?

Common submultiples of a Coulomb include microcoulombs (μC = 10^-6 C), nanocoulombs (nC = 10^-9 C), and picocoulombs (pC = 10^-12 C). These are used for measuring smaller amounts of charge.