Deriving the electron speed from a specified orbital

AI Thread Summary
The discussion focuses on calculating the speed of an electron in the n = 3 state of a hydrogen atom. The user initially uses the energy equation En = -E0(z^2/n^2) and attempts to derive the speed using momentum and the relationship p = mv. However, they encounter issues with their calculations and seek clarification on the correct approach. The conversation also touches on the total energy of the electron being negative and questions the validity of using E = pc for an electron. Understanding the energy-momentum relationship and the implications of negative energy in atomic systems is crucial for accurate calculations.
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[Mentor's note: this thread was moved from a non-homework forum, therefore it does not use the normal template for homework questions]

What is the speed of the electron in terms of the speed of the light when it is in the n = 3 state in the Hydrogen atom?

I started with this equation to find the energy En=-E0(z^2/n^2)
From that i used the momentum=E/c and found momentum then derived v from p=mv
The system keeps saying I am wrong, is there anything specific I am missing or maybe an equation i should be using instead?
 
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jason0294 said:
What is the speed of the electron in terms of the speed of the light when it is in the n = 3 state in the Hydrogen atom?

I started with this equation to find the energy En=-E0(z^2/n^2)
From that i used the momentum=E/c and found momentum then derived v from p=mv

Read http://en.wikipedia.org/wiki/Energy–momentum_relation

Is E=pc true for an electron?

The total energy of the electron in the Hydogen atom is negative. What do you think, why?

ehild
 

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