Sketch an energy level diagram showing the approximate relative energies of the 1 s, 2 s and 2 p

step 1 All right. In this question, we are asked to sketch an energy level diagram for lithium. Not too

Sketch an energy level diagram showing the approximate...

Key Concepts

Orbital Energy Ordering in Multi-Electron Atoms versus Hydrogen-like Atoms

In hydrogen-like atoms, orbital energies are determined solely by the principal quantum number (n), meaning that orbitals with the same n value (like 2s and 2p) are degenerate. However, in multi-electron atoms, electron-electron repulsions, shielding, and penetration effects lift this degeneracy, often resulting in a lower energy for orbitals that penetrate more effectively, such as the 2s orbital compared to the 2p orbital.

Electron Shielding and Penetration

Electron shielding occurs when inner electrons reduce the attractive force of the nucleus on outer electrons, while electron penetration refers to the ability of an electron in a particular orbital to get closer to the nucleus. These effects cause variations in energy ordering among orbitals; for instance, orbitals with greater penetration (even if in a higher principal quantum level) can end up being lower in energy in multi-electron atoms.

Effective Nuclear Charge

The effective nuclear charge is the net positive charge experienced by an electron in an atom after accounting for the shielding effects of other electrons. This concept is important for explaining the differences in orbital energies between different atoms, as electrons closer to the nucleus experience a stronger attraction compared to those further away.

Energy Level Diagrams

Energy level diagrams visually represent the arrangement of electron orbitals based on their energy. By systematically placing orbitals such as 1s, 2s, and 2p along an energy scale, these diagrams help in understanding the relative energies and the transitions that electrons can undergo between different states.

Atomic Orbitals

Atomic orbitals are mathematical functions that describe the regions in an atom where electrons are likely to be found. They are characterized by quantum numbers and come in various shapes and sizes (such as s and p orbitals), which influence the spatial distribution and energy of an electron in an atom.

Transcript

Please give Ace some feedback