Spectra Flashcards
How are electrons arranged in an atom?
In shells/orbitals around the nucleus of an atom
Explain the transition of electrons to another energy level.
When an electron gains energy, it transitions to a higher energy level which is also known as its excited state. After a while, the electron cannot capacitate the energy, so it emits it in the form of a photon, and transitions back to its ground state.
How do you excite electrons?
- Spark
- Heat
- Light - Light passed through a gas will have missing colours as they were used to excite an electron.
What does each atom have that is unique to others:
-Own unique spectra.
Line emission spectra?
Line emission spectra’s are produced after individual atoms have been excited, and return back to their ground state.
- Consists of bright lines on a black background
- Produce lines in the Infrared and ultra violet sections of the spectrum as well as the visible.
What are line emission spectra applications?
- Determining mineral composition of ores.
- Determining composition of stars.
- Producing light.
- Natural light shows.
Absorption spectra:
- Dark lines in the continuous spectrum.
- The valence electron absorbs a specific frequency of light that is then shown on the continuous spectra via its absence of presence.
- These frequencies are specific to each atom and are unique with one another due to varying numbers of electrons.
Continuous spectra?
- Consists of all the frequencies of light.
Is the frequencies re-emitted, if so why cant we see it?
The frequencies are emitted, but in all directions, so the intensity of that frequency in the viewers direction decreases overall, creating the ‘absence’ of it in the absorption spectra.
Techniques to identify the composition of a mixture/compound:
- Flame test
- Atomic absorption spectroscopy
