EL2 How Do We Know So Much About Outer Space? Flashcards
What is the scientific spectroscopy principle?
Under certain conditions, a substance can absorb or emit electro magnetic radiation in a characteristic way.
What does analysing a substance’s electromagnetic radiation tell you?
What the substance is and information about its structure and atoms.
What do glowing stars emit?
The light frequencies between the ultraviolet and infrared parts of the electromagnetic spectrum.
What does the sun emit?
Mainly visible light.
What do stars hotter than the sun emit?
Mainly ultraviolet radiation.
What is the region outside a stars surface called?
The chromosphere.
What is a stars surface called?
The photosphere.
What does the chromosphere contain?
Ions, atoms, and small molecules.
What do the particles from the chromosphere do?
Absorb some of the emitted radiation so that the light analysed from stars is missing certain frequencies.
What does the absorption spectrum look like?
The absorption lines appear black which lie on a coloured background.
Why are the absorption lines black on the absorption spectrum?
They are the missing frequencies absorbed by the chromosphere particles.
When does the frequency increase on the spectrum?
From left to right.
What happens to the particles in the chromosphere when they absorb energy?
They are raised from their ground state (lowest energy state) to higher energy states called excited states.
How can particles in the chromosphere lose their extra energy?
By emitting electromagnetic radiation.
What does the emission spectrum look like?
Frequencies emitted are as coloured lines on a black background.
What does white light contain and what kind of spectrum is it?
All the visible wavelengths, and a continuous spectrum.
What does light seen from stars consist of?
Lines corresponding to the absorption or emission of specific frequencies of light.
What particles are mainly in the suns chromosphere?
Hydrogen and helium atoms.
What do hydrogen atoms do?
Dominate the chromosphere’s emission spectrum, with seen helium lines as well.
What do both emission and absorption spectrums of the same substance do?
They frequencies match up exactly.
What is the balmer series?
The hydrogen emission spectrum in visible light.
What is the lyman series?
The hydrogen emission spectrum in ultraviolet light.
What do hydrogen atoms have emission spectrums in?
Visible light and ultraviolet light.
What is spectroscopy a study of?
The interaction of light and matter.
What are the two atomic spectra?
Absorption spectra and emission spectra.
What are the two models that describe the behaviour of light?
The wave theory and particle theory.
What characteristics does light have and why?
Wavelength and frequency, its a form of electromagnetic radiation so it behaves like a wave.
What is the speed of light when travelling in a vacuum?
3.00 * 10^8 ms^-1
What do different colours of light have?
Different wavelengths.
What is the equation for the speed of light?
Speed of light(ms) = wavelength (m) * frequency (s)
What is the frequency of a wave?
The number of waves that pass through a point each second.
What is the wavelength of a wave?
The distance from a point on one wave to the same point on another.
What is light regarded as in the particle theory of light?
Tiny packets of energy called photons.
What is the energy of a photon related to?
The position of the light in the electromagnetic spectrum.
What is the equation for an energy of a photon?
Energy of a photon (J) = planck constant (Js) * frequency (s)
