Modern physics: Atomic Structure

AI Thread Summary
The discussion focuses on calculating the average potential energy of an electron in the ground state of hydrogen due to its Coulomb interaction with the nucleus, using the Bohr radius as the average radius of the electron wave function. The relevant equation for potential energy is provided, but there are uncertainties regarding the values used, particularly the meaning of 'e' and whether it refers to the electron charge or mass. Participants suggest clarifying units and the correct interpretation of constants to resolve the calculation issues. The conversation emphasizes the importance of understanding the physical meaning behind the variables in the formula. Overall, the thread highlights the complexities of atomic structure calculations in modern physics.
ira
Messages
2
Reaction score
0

Homework Statement


If we take the average radius of the electron wave function in the ground state of hydrogen to be the Bohr radius, calculate the average potential energy of the electron due to the Coulomb interaction with the nucleus. State answer in eV.

Homework Equations


I think the relevant equation is V(x)= -(e^2) / [ 4(pi)(epsilon naught)(delta x) ]

The Attempt at a Solution



1/[4(pi)(epsilon naught)] = constant = 8.9876x10^6
The Bohr radius= 5.29x10^-11 m <--- (is this delta x?)
e = 0.511 MeV =5.11x10^5 eV (is this even correct? does 'e' mean the electron charge or mass?)

V(x)= [[-(0.511)^2] . (9.9876x10^6) ] / 5.29x10^-11
=4.436x10^28

As you can see I have many doubts. Hope any of you physics genius can help!
 
Physics news on Phys.org
ira said:
e = 0.511 MeV =5.11x10^5 eV (is this even correct? does 'e' mean the electron charge or mass?)
What do you expect in a formula for the potential of a charged object in the field of another charged object?

Just work with units, then you'll see what went wrong.
 
So, does e mean the mass of electron?
 
Do the units match if you plug in a mass?
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top