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.
