ASTRO 7N - Unit 3, Part 1: The Sun Lesson

The sun's radius is 109 times the Earth's radius. That would mean you could fit about __________ Earths inside the sun's volume.

1 million

The mass of the sun is about 333,000 Earths. About how much of the total mass of all object sin the solar system is contained in the sun alone?

99%

What is the first step in the p-p chain?

A proton combines with a proton to make Hydrogen-2 (deuterium)

What else do you see? (in last step)

Again, a burst of energy and helium-4 is produced, with two protons moving off to the side.

Why was there a big burst of energy? (seen in 1st step)

Because the mass of the particles starting the reaction is more than that of the products. Mass is converted to energy via E=mc^2

Can you tell me how many protons a hydrogen atom (H) has, and how many protons a helium atom (He) has?

Hydrogen has 1 proton, and helium has 2 protons.

What is the second step in the reaction?

Hydrogen-2 combined with an additional proton, to make helium-3

What is the sun?

It is a star just like the stars we see in the nighttime sky.

What happened to the protons during the first step of the chain?

One of the protons converted into a neutron, still contained with the hydrogen-2

What happened? (in 2nd step)

again there is some energy released (a gamma-ray photon) and we end up with helium-3 (this happens TWICE)

What is the final step in the p-p chain?

helium-3 combines with another helium-3 to make helium-4 (and two protons are left over)

Like how we humans, and animals, etc., all glow in __________.

infrared

The energy output of the sun is about 4*10^26 Watts. What physical process could generate that kind of energy?

nuclear fusion

In the sun, the proton-proton chain makes 4He (helium-4) the dominant form of helium. 4He has...

two protons, because it is helium, and two neutrons to make 4 total particles in the nucleus