The brilliant color of fireworks is produced by shells containing lithium carbonate (Li2CO3) that are
launched into the night sky and explode. The explosions produce enough energy to vaporize the Li2CO3
and produce excited state lithium atoms. These atoms quickly lose energy as they transition from their
excited states to their ground states, emitting photons of red light that have a wavelength of 670.8 nm.
a) (3 marks) Calculate the energy (Joules) in each photon of red light emitted by an excited lithium
b) (2 marks) Calculate the energy of one mole of these photons (kJ/mol).
c) (1 mark) Li atoms in the lowest energy excited state above the ground state emit these red photons.
What is the difference in energy (J) between the ground state of a Li atom and its lowest-energy
d) (1 mark) What is the electron configuration of a ground-state Li atom?
e) (1 mark) What is the electron configuration of a Li atom in its lowest-energy excited state?
f) (1 mark) What region of the
How would you do c and e ? Thanks in advance
delta E = hc/lambda
1s2 2s1 is the ground state.
delta E = 2.180E-18(1/1^2 - 1/x^2)
Solve for x and that is the energy level of the excited state giving the red light. When you know x, then 1s2 2x1. My guess without doing any of the calculation is 2p. The selection rule in spectroscopy is that delta l = +/- 1 so if ground state of the 2s1 electron is 0 (s electrons l = 0) then+1 would be to a p orbital where l = 1.
Post your work if you get stuck.posted by DrBob222