Energy uncertainty of an atom in an excited state

[Ezequiel]

Homework Statement

A Na atom is in an excited state for a mean time of $1.6 \times 10^{-8}s$. Then it jumps to the ground state emitting a photon with 2.105 eV of energy. Find the energy uncertainty of that excited state.

Homework Equations

The Attempt at a Solution

I don't even know where to start. Any help would be appreciated!

 

[Saitama]

Uncertainty principle?

http://hyperphysics.phy-astr.gsu.edu/hbase/uncer.html

 

[Ezequiel]

I just don't know how to use that to solve the problem. Could you be more specific?

 

[Ezequiel]

Could it be $\Delta E > \frac{\hbar}{2} \frac{1}{\Delta t} = 32.96 \times 10^{-28}J$?

 

[sankalpmittal]

Could it be $\Delta E > \frac{\hbar}{2} \frac{1}{\Delta t} = 32.96 \times 10^{-28}J$?

Doesn't seem to be correct. What you did basically? And the question mentions Na atom , so we cannot use bohr equations. Also I don't know why they gave you energy of de-excitation. There is no use of it , I guess... I think you used the correct equation but did not solve it correctly.