Question

When a metal plate is given a positive charge, which of the following is taking place? a) Protons (positive charges) are transferred to the plate from another object. b) Electrons (negative charges) are transferred from the plate to another object. c) Electrons (negative charges) are transferred from the plate to another object, and protons (positive charges) are also transferred to the plate from another object. d) It depends on whether the object conveying the charge is a conductor or an insulator.

Short answer

Answer: Electrons (negative charges) are transferred from the plate to another object.

Step-by-step solution

Review charging processes of conductors

When charging conductors, there is a transfer of charges (either positive or negative) between objects. We know that protons are fixed in the nucleus of an atom and do not move, while electrons are mobile and can be transferred from one object to another.

Evaluate each of the given options

a) Protons (positive charges) are transferred to the plate from another object: This option can be discarded because protons do not move, only electrons can be transferred during the charging process. b) Electrons (negative charges) are transferred from the plate to another object: This option describes the process of removing negative charges (electrons) from the metal plate, leaving it with a net positive charge. c) Electrons (negative charges) are transferred from the plate to another object, and protons (positive charges) are also transferred to the plate from another object: This option can be discarded because, as previously mentioned, protons do not move and cannot be transferred between objects. d) It depends on whether the object conveying the charge is a conductor or an insulator: This option can be discarded since both conductors and insulators can transfer a charge, but the underlying process of charge transfer (electron movement) does not change based on the type of material involved.

Choose the correct answer

Based on our evaluation of each option, the correct answer is (b) Electrons (negative charges) are transferred from the plate to another object. When the metal plate is given a positive charge, negative charges (electrons) are transferred from the plate to another object, leaving the plate with a net positive charge.

Key concepts

Electron Transfer in Charging Conductors

The process of charging conductors primarily involves the movement of electrons. Let's delve into what electron transfer means. Electrons are the subatomic particles that carry a negative electrical charge. They are also the components of atoms that are free to move, especially within conductors like metals.

During the charging process, a conductor becomes positively charged not by gaining positive particles, but by losing negatively charged electrons. This is a fundamental concept in understanding electrical charging. It's a common misconception that a positively charged object has received positive charges; in truth, it has simply lost some negativity, that is, electrons. The existing solution demonstrates this idea clearly by stating that when a metal plate is given a positive charge, it's actually because electrons have moved away from the plate to another object.

Visualizing Electron Transfer

Imagine electrons as a group of birds sitting on a metal plate. If some of those birds fly away, the plate will have fewer birds. Similarly, when electrons are transferred away from a metal plate, the plate's net charge becomes positive because there are now fewer negative charges (electrons) present.

Understanding Positive and Negative Charges

Positive and negative charges are fundamental to the concept of electricity. Positive charges are carried by protons, while negative charges are carried by electrons. It's crucial to remember that protons are located in the atom's nucleus and are virtually immobile, whereas electrons can move from one atom to another.

This movement of electrons, or lack thereof, defines the charge of an object. When electrons leave an object, they leave behind the positive charges of the protons, which results in the object being positively charged. Conversely, if an object gains electrons, it becomes negatively charged. The exercise provided clearly aligns with this principle by illustrating that when a metal plate is positively charged, it's due to the loss of negatively charged electrons, rather than the addition of positive charges.

Charge Imbalance and Flow

Charging involves creating an imbalance of charges: adding electrons creates a negative charge, while removing electrons creates a positive charge. This imbalance can cause a flow of electrons when a pathway is provided, which we recognize as electrical current.

Properties of Conductors and Insulators

Conductors and insulators are distinguished by their ability to allow the flow of electrical charges. Conductors, such as metals, are materials that allow electrons to move freely through them. This is due to the structure of a conductor's atoms where the outer electrons are not tightly bound to their nuclei, allowing them to move and carry charge from one place to another.

Insulators, on the other hand, have tightly bound electrons that do not move easily. This means that insulators prevent or significantly restrict the flow of electrons, and therefore the transfer of charge. Common insulators include rubber, glass, and plastic. When considering the exercise's question about charging a plate, we disregard whether the object is a conductor or an insulator in the transfer process, as the solution indicates this doesn't affect the basic principle of electron transfer.

Applications in Everyday Life

Understanding the different properties of conductors and insulators is crucial in designing circuits and electrical devices. We use insulators to protect us from accidental contact with electrical currents and conductors to direct and control the flow of electricity within a circuit.