What Is the Minimum Energy Required to Break a Molecule Apart?

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SUMMARY

The minimum energy required to break a molecule apart from its ground state is determined by the difference between the bound and unbound states, measured in electron-volts (eV). The discussion emphasizes that the energy levels of a molecule are quantized, and to transition to an unbound state, sufficient energy must be supplied. Additionally, the inertial mass of a molecule varies with its energy state, necessitating calculations to determine the mass difference between the highest-energy bound state and the ground state. The relevant equations include the photon energy formula and the relationship between energy and mass.

PREREQUISITES
  • Understanding of quantum mechanics and energy quantization
  • Familiarity with electron-volts (eV) as a unit of energy
  • Knowledge of the relationship between energy and mass in physics
  • Basic grasp of photon energy calculations using Planck's constant
NEXT STEPS
  • Study the concept of quantized energy levels in molecules
  • Learn about the relationship between energy and mass in the context of relativity
  • Explore calculations involving photon energy and wavelength using E_photon = hc/λ
  • Investigate the implications of bound and unbound states in molecular physics
USEFUL FOR

Students studying quantum mechanics, physicists interested in molecular energy states, and educators teaching advanced physics concepts related to energy and mass.

Sheldonpayne
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Homework Statement


Potential energy in a molecule[/B]

8.P.027_LennardJones1WA.jpg

(b) The figure below shows all of the quantized energies (bound states) for one of these molecules. The energy for each state is given on the graph, in electron-volts (1 eV = 1.6 ✕ 10-19 J). What is the minimum amount of energy required to break a molecule apart, if it is initially in the ground state? (Note that the final state must be an unbound state; the unbound states are not quantized.)
eV
08-035-LennardJones2.jpg
(c) If the temperature is high enough, in a collection of these molecules there will be at all times some molecules in each of these states, and light will be emitted. What are the energies in electron-volts of the emitted light? List them from smallest to greatest.

(d) The "inertial" mass of the molecule is the mass that appears in the definition of momentum, and through the momentum principle the inertial mass determines how much acceleration will result from applying a given force. Calculate the difference between the inertial mass of a molecule in the highest-energy bound state and the inertial mass of a molecule in the ground state.

Homework Equations



D), delta_p=Fnet*delta_t
F X time = momentum
1 eV = 1.6e10-19J
E_N = -(13.6 eV)/N^2, where N is a nonzero positive integer
Photon energy and wavelength: E_photon = hc/gamma_light (h= Plancks constant)

The Attempt at a Solution



D), There should be no difference. The energy levels correspond to dierent types of energy not to a change in mass. I put 0 Kg but is incorrect. SO there is an actual change in MASS, but need help how to calculate it. Thanks!
 
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Welcome to PF!

Maybe the question is asking you to take into account relativity (very small effect).

Note: The equation En = -(13.6 eV)/n2 for the energy levels of the hydrogen atom is not relevant here.
 

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