Energy levels
Details the discrete energy states of electrons in an atom, including ground state, excited states, and ionization energy.
What is Energy levels?
A discrete, specific energy value that an electron can possess within an atom.
Key formula / rule: Energy of nth level in Hydrogen-like atom
Key points
- Understand the concept of quantized energy levels.
- Differentiate between ground state and excited states.
- Explain the process of photon absorption and emission.
- Calculate the energy of emitted/absorbed photons.
Common exam trap
Assuming electrons can have any energy value.
Definitions
- Term
Energy Level
- Meaning
A discrete, specific energy value that an electron can possess within an atom.
- Term
Ground State
- Meaning
The lowest possible energy state of an electron in an atom.
- Term
Excited State
- Meaning
Any energy state of an electron in an atom that is higher than the ground state.
- Term
Ionization Energy
- Meaning
The minimum energy required to remove an electron from an atom or molecule in its ground state.
Learning objectives
Understand the concept of quantized energy levels.
Differentiate between ground state and excited states.
Explain the process of photon absorption and emission.
Calculate the energy of emitted/absorbed photons.
Define and calculate ionization energy.
Formulae
- Name
Energy of nth level in Hydrogen-like atom
- Note
Z is atomic number, n is principal quantum number (1, 2, 3...).
- Expression
En = - (Z2 * 13.6) / n2 eV
- Name
Energy of photon absorbed or emitted
- Note
Ef is final energy level, Ei is initial energy level, h is Planck's constant, ν is frequency.
- Expression
ΔE = Ef - Ei = hν
- Name
Ionization Energy
- Note
For Hydrogen, IE = 0 - (-13.6 eV) = 13.6 eV.
- Expression
IE = E_∞ - Eground
Prerequisites
Atomic structure (protons, neutrons, electrons).
Basic understanding of electromagnetic radiation.
Coulomb's law.
Common mistakes
Assuming electrons can have any energy value.
Confusing absorption and emission processes.
Incorrectly calculating energy differences between levels.
Keywords
Energy levels
Quantization
Bohr model
Ground state
Excited state
Photon
Ionization energy
Atomic spectra
Principal quantum number
Practice preview
When an electron absorbs energy and moves to a higher energy level, the atom is said to be in which state?…
easy
What is the lowest energy level an electron can occupy in an atom called?…
easy
The energy levels of a hypothetical one-electron atom are given by E_n = -18.0/n^2 eV, where n = 1, 2, 3, ... . If an electron is in the n=3 state and absorbs a photon of energy 4.0 eV, what will be its final energy stat…
hard