EL2 - Atomic Spectra Flashcards
(23 cards)
What are the characteristics of the ultraviolet side of the electromagnetic spectrum?
High frequency
Short wavelength
High energy
What are the characteristics of the infrared side of the electromagnetic spectrum?
Low frequency
Long wavelength
Low energy
What has a lower energy than infrared?
Radiowaves
What has a higher energy than ultraviolet?
X-rays, then Gamma rays
What is the name for the study of how light and matter interact?
Spectroscopy
What are the two theories explaining light, neither of which does so fully?
Wave theory and Particle theory.
λ (lambda) = ?
Wavelength (m)
As wavelength increases, frequency…
Decreases
v = ?
frequency Hz or s-1
c = ?
The speed of light
What is the equation triangle for speed of light, frequency and wavelength?
C
λ v
What is the equation for energy in the particle model of light?
E = hv
What is Bohr’s theory?
-electrons become excited when they gain energy
- they can lose this energy again
- when they lose it they emit radiation
- the frequency of this radiation is fixed so electrons must exist in definite energy levels
- when they move from a higher to lower energy level they emit photons.
The energy of these photons is equal to the difference between the two energy levels
What would a hydrogen emission spectrum look like if electrons didn’t only exist in fixed energy levels?
Instead of specific frequencies, every frequency would be observed
What is a Quanta?
A fixed quantity of energy
Electrons can move from ____ to _____ energy levels. Emitting photons of a particular energy, which corresponds to the energy gap between the 2 levels.
Higher to Lower
The higher frequencies on the emission spectra correspond to …..
The largest energy gaps
What is the name for the hydrogen emission spectra
The Lyman Series
What is an absorption spectra?
It shows all the frequencies of radiation expect any being absorbed.
On an absorption spectra, absorbed frequencies will appear as _____
Black lines on a coloured background
For a particular element the frequencies of these black lines correspond to those observed on the ….
Emission spectra
Why do some elements have characteristic flames?
Because the energy of photos emitted corresponds to a wavelength on the visible spectrum.
What are the flame colours of - Lithium Sodium Potassium Calcium Barium Copper
Lithium - bright red Sodium - yellow Potassium - lilac Calcium - brick red Barium - apple green Copper - blue green
