EL 2 Flashcards
what is the absorption spectra?
black lines on a coloured background (missing frequencies of light which have been absorbed)
chromosphere absorbs radiation
raised from ground state to excited state
the black lines is the light from stars that is missing at certain frequencies
what is the emission spectra
coloured lines on a black background (frequencies of light being emitted)
when chromosphere absorbs energy the are raised from ground state to excited
particles lose extra energy by emitting radiation causing light
flame test elements and colours
Barium- apple green
Calcium- brick red
Copper- green with blue streaks
Lithium- crimson
Potassium- lilac
Sodium- yellow
what is the equation for the wave theory of light
speed of light = wavelength x frequency
c = / x v
what is the equation for the particle theory of light
energy of a photon = planck constant x frequency
E = h x v
what is the wave theory of light
the speed of the wave is the same for all light and EM radiation (speed of light)
different colours of light have different wavelengths
as wavelength increases frequency decreases
speed of light= wavelength x frequency
what is the particle theory of light
energy of light relates to the position of light in the EM spectrum
tiny packets of energy- photon
energy of a photon = planck constant x frequency
what is Bohr’s theory
-photon of light is emitted/absorbed when the electron changes from one energy level to another
-energy level of a photon is equal to the difference between two energy levels
-lines are closer together at higher frequencies
-lines are further a part at higher wavelengths
-both lines exactly correspond to each others lines
-electron in hydrogen atom exists only in certain energy levels (electron shells)
what is spectroscopy
substances absorbing or emitting EM radiation under certain conditions
what is the continuous spectra
light that contains all wavelengths without any gaps (white light)
no gaps or lines
what is the atomic spectrum of hydrogen atoms
emission of hydrogen in visible light - Balmer series
emission of hydrogen in ultraviolet light - Lyman series
does the energy level of an electron increase the further you get from the nucleus and why
yes
electron becomes exited and jumps up from ground state to higher energy levels
why can electrons only reach specific energy levels
electrons only possess definite quantities of energy (quanta)
electrons have specific energy levels
gain energy = jump to higher level
loose energy = fall down to ground state
what does the position of the lines on the spectra’s represent
lines are closer together at higher frequencies
lines are further a part when wavelength increases
what happens to frequency as wavelength increases
frequency decreases (inversely proportional)
what does a mass spectrometer do
determines isotopes present in and element
measures mass- charge ratio of cations
