Chapter 19 - Stars

Question 1

Define nebulae.

Answer 1

Nebulae are massive clouds of dust and mostly hydrogen gas, which become the elements that form a star.

Question 2

How are stars born?

Answer 2

1. A nebula is formed over millions of years.
2. The dust and gas get closer until a gravitational collapse, becoming denser and hotter (transfer from GE to Thermal Energy).
3. A protostar forms within the clouds, a very hot sphere of dust and gas.
4. Once the protostar forms, nuclear fusion happens after it is dense and hot enough to overcome electrostatic repulsion.

Question 3

How is equilibrium achieved in a stable star?

Answer 3

• Outwards pressure from the core is achieved by radiation pressure from the photon generation during fusion and gass pressure from the nuclei in the core.
• Inwards pressure is caused by gravitational forces.

Question 4

Define a planet.

Answer 4

Question 5

Define a dwarf planets.

Answer 5

Question 6

Define Asteroids.

Answer 6

Question 7

Define Planetary Satelllites.

Answer 7

Question 8

Define comets.

Answer 8

Question 9

Define Solar Systems.

Answer 9

Question 10

Define Galaxies.

Answer 10

Question 11

How much is a Solar Mass, M☉, approximately?

Answer 11

A solar mass is about 1.99 x 10³⁰ Kg.

Question 12

What size of star will turn into a red giant?

Answer 12

Question 13

Describe a red giant.

Answer 13

Question 14

What is the phase after a red giant?

Answer 14

Question 15

Define electron degeneracy pressure.

Answer 15

Question 16

What is the Chandrasekhar limit?

Answer 16

Question 17

Define a neutron star.

Answer 17

Question 18

Define a black hole.

Answer 18

Question 19

What is the Schwarzschild radius.

Answer 19

Question 20

Describe a Hertzsprung-Russell Diagram

Answer 20

Question 21

What are the 4 rules about energy levels of an electron?

Answer 21

Question 22

What is it called when an electron moves from a lower to a higher energy level?

Answer 22

Question 23

How do you find the frequency of a photon, when an electron jumps a valency?

Answer 23

Question 24

Define each of the three spectra.

Answer 24

Question 25

Define a diffraction grating.

Answer 25

Question 26

What can be used instead of a double slit for spectral analysis?

Answer 26

Question 27

How do you determine the wavelength of monochromatic light?

Answer 27

Question 28

What is a black body?

Answer 28

Question 29

What is Wien's Displacement Law?

Answer 29

Question 30

What is Stefan's Law?

Answer 30