4103FSBMOL - Lecture 2 - Introduction to Spectroscopy. Flashcards
Electromagnetic Readation/ Spectrum, UV/Visible Spectroscopy and Infrared Spectroscopy.
What is the definition of Spectroscopy?
The interaction between light and matter as a function of a wavelength (λ).
What is the definition of a Spectrum?
Plot (graph) of the response as a function of the wavelength. (x-axis = wavenumber, y-axis = % absorption).
What is the definition of Spectrometry?
The measurement of the responses.
What is Electromagnetic Radiation (EM)?
It is radiation which contains bundles of energy known as photons. Photons are really unstable, move very fast and don’t have a mass. They can be in the form of waves or particles and as a wave, electromagnetic energy is determined as a wavelength, wavenumber or frequency.
What is Planck’s Equation?
E = h v.
What does ‘E’ stand for in E = h v?
Energy.
What does ‘h’ stand for in E = h v?
Planck’s Constant.
What does ‘v’ stand for in E = h v?
Frequency.
What version of Planck’s Equation can you use if you don’t have a frequency?
E = hc / λ.
What does ‘E’ stand for in E = hc / λ?
Energy.
What does ‘h’ stand for in E = hc / λ?
Planck’s Constant.
What does ‘c’ stand for in E = hc / λ?
Speed of light.
What does ‘λ’ stand for in E = hc / λ?
Wavelength.
What units is Wavelength measured in?
cm-1.
What is the name for the top part of a wave?
Peak.
What is the name for the bottom bit of a wave?
Trough.
What is the name for the distance between 2 peaks of a wave?
Wavelength.
What is the name for the distance between the peak and the trough?
Amplitude.
What happens to the energy if the wavelength increases?
It also increases.
What equation can you use to be the frequency from speed of light and wavelength?
v = c/λ.
v = Frequency.
c = Speed of Light.
λ = Wavelength.
How do you describe the wavelength?
The distance travelled over a complete wave cycle.
How do you describe the Wavenumber?
The number of waves per centimetre (cm).
How do you describe the Frequency?
The number of wavelengths which pass through a certain point every second.
What type of radiation is consisted of in the Electromagnetic Spectrum?
Polychromatic Radiation (multiple colours).
This makes it less dangerous.