Using Maxwell Boltzmann distribution to find number of atoms

AI Thread Summary
The discussion focuses on calculating the number of mercury atoms in the first excited state using the Maxwell-Boltzmann distribution. The energy difference between the ground state and the first excited state is given as 4.86 eV, with a sample containing 1.06×10^20 atoms at 1563 K. The participant successfully normalized the distribution and determined the constant A to be 3.854. They also identified the statistical weights for the ground and excited states, noting 2 states for n=1 and 8 for n=2. The participant ultimately resolved their confusion regarding the integration limits needed for the calculation.
dinospamoni
Messages
90
Reaction score
0

Homework Statement



You will recall from our discussion of the Franck-Hertz experiment that the energy difference between the first excited state of mercury and the ground state is 4.86 eV. If a sample of mercury vaporized in a flame contains 1.06×1020 atoms in thermal equilibrium at 1563 K, calculate the number of atoms in the first excited state. Assume that the Maxwell-Boltzmann distribution applies and that the n = 1 (ground) and n = 2 (first excited) states have equal statistical weights.

Homework Equations



The Maxwell-Boltzmann distribution:

f(E)=A e^{\frac{E}{k_{b}T}}

where A is a constant
k_b is the Boltzmann constant = 8.617*10^-5 eV/K
and T is the temperature

n(E)dE = g(E) * f(E) dE

where n(E) = # per unit energy
g(E) = # of states per energy E
f(E) = MB distribution

The Attempt at a Solution



I'm still having trouble learning how to use distributions, so bear with me (or help me understand it :))

I started off by normalizing the distribution by:

\int\limits_0^\infty f(E)^2 dE

then I set it equal to 1 and solved for A. I found A=3.854.

I think that was the right first step.

and I know that g(E) for n=1 is 2 possible states
and n=2 has 8.

This is as far as I have gotten, as my professor hasn't really gone over how to use these distributions.

My guess is that I set

1.06*10^{20} = n_{1}(E) dE + n_{2} (E) dE <br /> <br /> after this I know I have to integrate, but I'm not sure how to set up the limits, among other things.
 
Physics news on Phys.org
never mind I figured it out!
 
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}...

Similar threads

Replies
3
Views
2K
Replies
2
Views
7K
Replies
3
Views
2K
Replies
16
Views
1K
Replies
22
Views
1K
Replies
4
Views
1K
Back
Top