The Electron Flashcards
How is electromagnetic radiation generated
Thermally induced motion of atoms/molecules
How do electrons in an uncharged atom surround the nucleus in
Shells
What does each shell correspond to
A fixed energy level and is capable of holding a certain number of electrons
How do electrons excite
By absorbing a photon that corresponds to the exact energy difference between levels
How do electrons de-excite
By emitting a photon that is the exact difference between energy levels
What are energy levels
Discrete values that electrons around a central nucleus can have
When is an atom said to be ionised
When it becomes a charged particle
What is the ionisation energy
Minimum energy needed to remove the electron from the atom completely
What is an electron volt
Unit of energy commonly used in atomic and nuclear physics equal to the energy gained by an electron when the electrical potential at the electron increases by one volt
What displays line spectra
Excited gases
What displays continuous emission spectra
Hot solids and liquids
How does line spectra work
When electric current passes through a sample of gas at very low pressure, light is emitted
What is the Balmer Series
Group of hydrogen spectral lines in the visible region
Define Fluorescence
Glow of visible light produced when a material is illuminated by ultraviolet
Define Phosphorescence
Emission of light from a substance which has been exposed to radiation and produces a persistent afterglow even after the exciting radiation has been removed
