30.5 Applications of Atomic Excitations and De-Excitations

A sample of hydrogen gas confined to a tube is initially at room temperature. As the gas is heated, the observer notices that the gas begins to glow with a pale pink color. Careful study of the spectrum shows that the light spectrum is not continuous. Instead, the hydrogen gas is only emitting visible wavelength photons of four specific colors, which combine to form the overall color to the human…

Which of the following is the best way of explaining why the leaves on a given tree are green?

1. The molecules in the leaves absorb all visible light but strongly reflect green light.
2. The molecules in the leaves absorb green light and reflect other visible light.
3. The molecules are excited by external light sources, and their electrons emit green light when they are de-excited to a lower energy leve…

An electron is excited from the ground state of an atom (energy level 1) into a highly excited state (energy level 8). Which of the following electron behaviors represents the fluorescence effect by the atom?

1. The electron remains at level 8 for a very long time, then transitions up to level 9.
2. The electron transitions directly down from level 8 to level 1.
3. The electron transitions from level 8 to…

the figure shows the energy-level diagram for neon. (a) Verify that the energy of the photon emitted when neon goes from its metastable state to the one immediately below is equal to 1.96 eV. (b) Show that the wavelength of this radiation is 633 nm. (c) What wavelength is emitted when the neon makes a direct transition to its ground state?