Astronomy Quiz 14

What factor determines the kind of life a star is going to lead?

• Temperature of star

• Size of star

• Mass of star

• Speed of light

A star can be a supernova

• Many times

• At various times, depending on the mass of the star

• Only once

• Before it reaches the main sequence in some cases

Which of the following elements in your body is formed in stars?

• Carbon

• Oxygen

• Calcium

• Iron

• All of the above

If a star is in hydrostatic equilibrium

• It is in a stable binary orbit

• It is generating energy at the same rate everywhere

• It is near the end of its life

• It must be losing mass

• Its radiation pressure outwards and gravitational forces inwards are in balance

Which of the following statements about planetary nebulas is correct?

• They are shells of glowing gas and dust ejected by dying Sun-like stars

• They contain flakes of carbon and silicon material

• They expand at a typical rate of 20 kilometers per second

• Their shape can be very irregular

• All of the above

Which of the following statements apply in the final moments of the life of high-mass stars?

• Their outer layer is mainly hydrogen and helium

• Below the surface there is a series of nested shells each made of a lighter element than the one below it

• They have iron cores

• The core temperature is about 2 billion degrees

• All of the above

The CNO cycle produces energy by fusing _____ into ____.

• Oxygen; nitrogen

• Hydrogen; helium

• Carbon; helium

• Helium; carbon, nitrogen and oxygen

The triple alpha process produces energy by fusing ____ into ____.

• Helium; carbon

• Hydrogen; helium

• Oxygen; carbon

• Oxygen and carbon; carbon dioxide

• Carbon and nitrogen; cyanogen

After the hydrogen in the star's core is depleted the core ____ and ____.

• Cools down; shrinks

• Shrinks; heats up

• Heats up; expands

The last fusion product possible in stars is _________ because _________.

• Lead, fusing lead nuclei absorbs energy, it does not liberate it.

• Iron, fusing iron nuclei absorbs energy, it does not liberate it.

• Iron, no stars are hot enough in their cores to fuse iron nuclei.

• Carbon, no stars are hot enough in their cores to fuse carbon nuclei.