Electron Energy Levels and Photons

This video introduces energy levels and explains why line spectra occur. Electrons surround the nucleus in discrete shells, each with specific energy. Electrons can be excited to higher energy levels by current or electromagnetic radiation. When they return to lower levels, they emit photons with energy equal to the difference between levels, creating line spectra. An example with mercury vapor demonstrates possible photon energies and maximum wavelength calculations.

What is the maximum number of electrons that the second shell can hold?

• 8

• 2

• 4

• 6

What is the ground state in terms of energy levels?

• The highest energy level

• The lowest energy level

• An intermediate energy level

• A non-existent energy level

What is required for electromagnetic radiation to excite electrons?

• More energy than needed

• Less energy than needed

• Precisely the excitation energy

• Any amount of energy

What happens when an electron drops to a lower energy level?

• It emits a photon

• It gains energy

• It remains in the same state

• It absorbs a photon

Why do we see bright lines at particular frequencies in a line spectrum?

• Because of continuous energy levels

• Due to limited photon energies

• Because of random photon emissions

• Due to absorption of all photons

How many different photon energies can be emitted when an electron drops from 5.46 eV to the ground state?

• 6

• 5

• 4

• 3

What is the smallest possible energy transition in the given example?

• 4.67 eV to 0 eV

• 5.46 eV to 4.89 eV

• 5.46 eV to 0 eV

• 4.89 eV to 4.67 eV

What is the formula used to calculate the wavelength of a photon?

• E = mc^2

• E = hf

• E = λf

• E = hc/λ

What is the Planck constant used in the wavelength calculation?

• 6.63 x 10^-34

• 3.00 x 10^8

• 1.60 x 10^-19

• 9.81 m/s^2

What is the maximum wavelength of a photon that can be emitted in the example?

• 5.65 micrometers

• 5.65 centimeters

• 5.65 nanometers

• 5.65 millimeters