Chapter 11

Question 0

Nuclear potential energy (core) / luminosity

Answer 0

10 billion years

Question 1

E =

Answer 1

Mc^2

Question 2

Gravitational equilibrium is the perfect balance between what?

Answer 2

Pressure and gravity

Question 3

What is the radius of the sun?

Answer 3

6.9 x 10^8

109 times the earth

Question 4

There is a balance within the sun between..

Answer 4

Outward push of pressure and inward pull of gravity

Question 5

What is the solar (star) system?

Answer 5

A star and all the material that orbits it, including its planets and moons

Question 6

What is the composition of the sun?

Answer 6

70% hydrogen
28% helium
2% heavier elements

Question 7

What is the rotation rate of the sun?

Answer 7

25 days (equator)
30 days (poles) 
-differential rotation

Question 8

What is the Suns structure?

Answer 8

Chromosome (hot, UV)

Corona (hotter, X-ray)

Question 9

Hotter objects emit what two things?

Answer 9

• more light at all frequencies per unit area

- photons with higher average energy.

Question 10

Define fission

Answer 10

Big nucleus SPLITS into smaller pieces (nuclear power plants)

Question 11

Define fusion

Answer 11

Small nuclei STICK together to make bigger one (sun, stars)

Question 12

Heavy chemical elements break into small particles and do what?

Answer 12

Generate energy

Question 13

In low temperatures protons do what?

Answer 13

Repel

Question 14

In high temperatures protons do what?

Answer 14

Collide

Question 15

High temperatures enable ___________ to happen in the core

Answer 15

Nuclear fusion

Question 16

The sun releases energy by fusing __________ nuclei into one ______ nucleus

Answer 16

4 hydrogen
One helium
(Pp chain)

Question 17

4 protons go in and what comes out?

Answer 17

He nucleus, 2 gamma rays, 2 positrons, 2 neutrinos

Total mass is .7% lower

Question 18

Energy ________ leaks out of the ________ zone in the form of randomly bouncing photons. How many years?

Answer 18

Gradually
Radiation

100,000 years!

Question 19

What two things do we compare to learn about the inside of the sun?

Answer 19

Mathematical models vs. observations of solar vibrations and neutrinos

Question 20

Patterns of _______ on the surface tell us about what the sun is like inside (inner structure)

Answer 20

Vibration

Referred to as helioseismology

Question 21

Data on solar vibrations agrees with what?

Answer 21

Mathematical models of solar interior

Question 22

Neutrinos created during fusing ____________ the sun

Answer 22

Fly directly through the sun

Question 23

How are neutrinos different from photons?

Answer 23

Photons interact with other particles and neutrinos don’t

Question 24

Why did early searches fail to find the predicted number of neutrinos?

Answer 24

Neutrinos changed form

Question 25

Sunspots are _____ than other parts of earths surface

Answer 25

Cooler

Question 26

Sunspots are regions with what?

Answer 26

Strong magnetic fields that only last a few weeks