Launch the Neon Lights & Other Discharge Lamps simulation. Observe how photons are emitted when different atoms are subjected to an electric current. You will see the energy transitions for electrons and the radiation frequencies they emit.

Instructions:
1. Click "Fire Electron" to fire an electron at the atom.
2. Select "Continuous" to bombard electrons at the atom continuously.
3. By default, the Hydrogen atom is selected. Select other elements from the "Atom Type" drop-down list.
4. The panel on the right shows changing energy levels as electrons hit the atom.
5. Select the "Spectrometer" check box to observe the wavelength and colors of emitted photons.
6. Select "Run In Slow Motion" to observe effects more clearly.
7. The "One Atom" tab places one atom at the center, while the "Multiple Atoms" tab places several atoms.

Try the simulation with different types of atoms to see how their energy levels change and the wavelengths of the generated photons. Observe the changes carefully, then answer the following questions.

Part A:
Select the "Run in Slow Motion" check box and fire an electron. Note the changes in energy levels on the right when the electron hits the atom. Explain why photons are released when a charged electron strikes an atom.