Question

Would moving an electron farther from an atom's nucleus give off light energy or require the absorption of light energy? Explain your answer.

Short answer

Moving an electron farther from an atom's nucleus requires the absorption of light energy. This is because when an electron transitions to a higher energy level, it moves away from the nucleus and needs an increase in energy, which is absorbed in the form of light energy or photons.

Step-by-step solution

Define the Problem

First, we need to identify the process that occurs when an electron moves farther away from the nucleus within an atom. An electron belongs to an energy level, and these energy levels are represented by concentric circles around the nucleus. When energy is added (absorbed), the electron moves farther out, and when energy is taken away (emitted), the electron moves closer in.

Review Electron Energy Levels

In an atom, electrons are arranged in energy levels around the nucleus. Electrons with the lowest energy levels are found closest to the nucleus, while those with higher energy levels are farther away. There's a specific limit of energy for each level, and an electron can't have energies above or below that defined limit.

Understand Energy Transition

When an electron absorbs energy, it transitions to a higher energy level, moving away from the nucleus. Conversely, when an electron emits energy, it transitions to a lower energy level and moves toward the nucleus. The energy released or absorbed during these transitions manifests as light energy or photons.

Identify the Process for the Problem

The exercise asks whether moving an electron farther from an atom's nucleus would give off light energy or require the absorption of light energy. In this case, the electron is moving away from the nucleus, meaning it is transitioning to a higher energy level.

Determine the Answer

Since the electron is moving to a higher energy level, which requires an increase in energy, it would need to absorb light energy for this transition. Therefore, the correct answer is that moving an electron farther from an atom's nucleus requires the absorption of light energy.

Key concepts

Atomic Structure

To fully understand why an electron moving away from an atom's nucleus requires the absorption of light energy, it's essential to begin with the basics of atomic structure.

At the center of every atom lies the nucleus, a dense core made up of protons and neutrons. Surrounding the nucleus, electrons whirl about in regions called energy levels or shells. These energy levels are akin to the rungs of a ladder; an electron can only reside on a rung, not in the space between the rungs. The closer an energy level is to the nucleus, the lower its energy. As one moves further out, these levels represent increasing quantities of energy.

Electrons naturally occupy the lowest available energy levels, a principle known as the 'ground state'. However, they can move to higher levels by gaining the right amount of energy. Just as adding a rung to a ladder requires materials and effort, pushing an electron to a higher energy level demands a specific quantity of energy, which often comes in the form of light.

Absorption of Light Energy

The phenomenon of absorption of light energy is intimately tied to the energy transitions of electrons within the atom.

Light is a form of energy that can be absorbed by electrons. When light strikes an atom, it carries energy - quantized in packets called photons. If the energy of the photon matches exactly the 'energy gap' between two electron energy levels, the electron can absorb this photon. This absorption is what enables the electron to leap from a lower energy level to a higher one.

Think of it as a person jumping from the ground onto a step; the person expends energy to make the jump, similar to how an electron absorbs energy to move to a higher level. This absorbed light energy must be just right; if the photon's energy is too little, the electron remains in its original position, and if it's too much, the photon might pass right by, leaving the electron unbothered.

Energy Level Transitions

Energy level transitions are the electron's leaps from one energy level to another within an atom, and these movements are governed by defined rules.

When an electron transitions to a higher energy level, we say it's in an 'excited state'. But electrons tend to be homebodies, preferring the coziness of the lowest possible energy level, or ground state. After absorbing energy and moving to a higher level, they don't stay there indefinitely. Eventually, they'll release energy and 'fall' back to a lower level. This release of energy often manifests as the emission of light, and the color of the light corresponds to the amount of energy released.

To summarize the process posed in our exercise: An electron moving farther from the nucleus means it's moving to a higher energy level, which defies its natural state. To achieve this positional shift, the electron must absorb the appropriate amount of light energy. Therefore, the action of moving an electron away from the nucleus is not one of giving off light but one of the absorption.