11.14 Habitable planet 1

Question 1

Initially following the big bang, what matter exist?

Answer 1

Hydrogen + Helium

No other chemical elements

Question 2

How are stars formed?

Answer 2

Gravitational collapse of Hydrogen and Helium / dust

Question 3

What is a star?

Answer 3

Spontaneous, sustained fusion reaction held together by gravity.

Question 4

What determines size of sun?

Answer 4

Equilibrium point between force of “hydrogen bomb” fushion reaction and gravity.

Question 5

What is required for fusion reactions to begin?

Answer 5

Very high temperatures.

This is accomplished by gravitational collapse of a sufficient mass.

Question 6

When elements are produced in nucleosynthesis (from stars)?

Answer 6

Elements up to iron.

Question 7

What causes a supernova?

Answer 7

When a star blows up, when it collapses due to gravity.

Question 8

How do we know what elements are in the sun?

Answer 8

Electromagnetic spectrum, specific wavelengths are blocked.