Average potential and kinetic energies for H ground state

In summary, to calculate the average potential and kinetic energies for the electron in the ground state of hydrogen, you can use the formula KE = E - <U(r)>, where E = (-KZ^2e^2)/(2a0) and U(r) = -KZe^2/r. Alternatively, you can directly calculate the expectation values for KE and U using integration or the Hellman-Feynman Theorem.
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tententententen
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Homework Statement


Calculate the average potential and kinetic energies for the electron in the ground state of hydrogen.

Homework Equations

The Attempt at a Solution


I know that KE = E - <U(r)>. I know that E = (-KZ^2e^2)/(2a0) and I know that U(r) = -KZe^2/r but I can't figure out how to get the average potential energy from this so that the denominator is the same as the E and so that they can add together to get KE.
 
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MisterX said:
You could always just calculate them directly by integration.
$$<KE> = \langle \psi \mid \frac{p^2}{2m}\mid \psi \rangle$$
$$<U> = \langle \psi \mid \frac{ke^2}{r}\mid \psi \rangle$$
You can also get some expectation values using the "Hellman-Feynman Theorem"
see https://en.wikipedia.org/wiki/Hellmann–Feynman_theorem#Expectation_values
Thanks a lot! That makes a lot of sense. I appreciate it!
 

1. What is the definition of potential energy?

Potential energy is the energy that a system possesses based on its position or configuration. It is the stored energy that can be converted into other forms, such as kinetic energy.

2. How does potential energy affect the energy of an atom in its ground state?

In the ground state, an atom's potential energy is at its minimum, meaning the atom is in its most stable state. This allows for the atom to have a lower potential energy and a higher kinetic energy.

3. What is the relationship between potential and kinetic energies for an atom in its ground state?

In the ground state, the potential energy and kinetic energy of an atom are equal. This is because the atom is in its most stable state and has no excess energy to be converted into kinetic energy.

4. How does temperature affect the average potential and kinetic energies of an atom in its ground state?

As temperature increases, the average kinetic energy of the atoms also increases. However, the average potential energy remains the same as it is determined by the atom's position and configuration, rather than temperature.

5. What is the significance of studying average potential and kinetic energies for the ground state of an atom?

Studying these energies can help us understand the behavior and stability of atoms in their ground state. It is also important for understanding chemical reactions and the transfer of energy in various systems.

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