Cosmology Flashcards
1
Q
How many km is one astronomical unit (AU)?
A
150 million km
2
Q
Define a light year.
A
1 light year is the distance travelled by light in one year
3
Q
At what point is an electrons energy taken to be zero?
A
When the electron is very far from the nucleus
4
Q
What is the ‘ground state’?
A
The lowest energy level closest to the nucleus.
5
Q
How is a line absorption spectrum formed?
A
A white light is passed through a cold gas and then a diffraction grating.
