Energy of Electrons: Explained

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    Electrons Energy
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Discussion Overview

The discussion revolves around the energy of electrons in relation to their distance from the nucleus and between each other. Participants explore concepts of electric potential energy, the implications of distance on energy levels, and the contrasting behaviors of attractive and repulsive forces. The scope includes theoretical explanations and conceptual clarifications.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that their textbook states that electrons further from the nucleus have higher energy levels, while also claiming that greater distances between electrons result in lower energy, expressing confusion over this contradiction.
  • Another participant emphasizes the importance of the sign in potential energy calculations, suggesting that it affects how energy comparisons are made.
  • A participant reiterates the initial confusion about energy changes with distance, questioning how energy can increase in one scenario (electron to nucleus) and decrease in another (electron to electron).
  • It is proposed that for attractive forces, potential energy increases with distance, while for repulsive forces, potential energy decreases with distance.
  • A later reply introduces the concept of a "Potential Well" as a mnemonic for understanding the signs of potential energy, suggesting that potential energy is zero at infinite distance and becomes negative as particles come closer together.

Areas of Agreement / Disagreement

Participants express confusion and differing interpretations regarding the relationship between distance and energy in various contexts. There is no consensus on how to reconcile the differing statements from the textbook.

Contextual Notes

The discussion highlights potential limitations in understanding the definitions of potential energy and the conditions under which these energy relationships apply. The participants do not resolve the mathematical or conceptual discrepancies presented.

henry3369
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So when my book explains energy of electrons it says that the further an electron is from the nucleus the higher the energy, which is why orbitals that are further away have higher energy levels. Then later in the chapter it explains that the greater the distance between two electrons, the lower the energy. I don't understand how the first case is possible. Electric potential energy = kq1q2/r, so increasing distance, decreases the electric potential energy. Also why would the energy of the electron depend on the charges (One situation the energy increases with distance while the other, energy decreases with distance)? Doesn't the sign just denote if it is attractive or repulsive, and the magnitude actually shows the energy?
 
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The sign is important . Comparisons are drawn based on the algebriac value of potential energy .
 
henry3369 said:
So when my book explains energy of electrons it says that the further an electron is from the nucleus the higher the energy, which is why orbitals that are further away have higher energy levels. Then later in the chapter it explains that the greater the distance between two electrons, the lower the energy. I don't understand how the first case is possible. Electric potential energy = kq1q2/r, so increasing distance, decreases the electric potential energy. Also why would the energy of the electron depend on the charges (One situation the energy increases with distance while the other, energy decreases with distance)? Doesn't the sign just denote if it is attractive or repulsive, and the magnitude actually shows the energy?

If a force is attractive, then the further away two particles are, the greater their potential energy.

If the force is repulsive, then the further away two particles are, the lower is their potential energy.
 
Theexpression "Potential Well" is a good description and a way of remembering which way round the sign goes. Start with zero potential at infinity (great distance) and fall down (negative) you get closer.
 

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