evolution of stars

What do we mean when we say that the Sun is in gravitational equilibrium (or hydrostatic equilibrium)?

A)There is a balance between the outward push of gas pressure and the inward pull of gravity at each point in the Sun.

B)The Sun always has the same amount of mass, creating the same gravitational force.

C)The Sun maintains a steady temperature at its surface.

A)There is a balance between the outward push of gas pressure and the inward pull of gravity at each point in the Sun.

Stars evolve because

A)they acquire a companion star

B)they increase in mass

C)they decrease in mass

D)their nuclear energy source changes

D)their nuclear energy source changes

Chapter 13 Question 36, page 360: What happens to the core of a high-mass star after it runs out of hydrogen?

A)Helium fusion begins right away.

B)It shrinks and cools down.

C)It shrinks and heats up.

C)It shrinks and heats up.

Main sequence stars begin life as

A)a cloud of gas and dust

B)a very hot planet

C)a very large planet

D)an explosion at the center of a newly forming solar system.

A)a cloud of gas and dust

Which of the following elements were created when the universe first formed?

A)all elements

B)hydrogen only

C)hydrogen and helium only

D)all elements except hydrogen

E)all elements heavier than helium

helium only

C)hydrogen and helium only

Chapter 13 Question 34, page 360: What would you be most likely find if you returned to the solar system in 10 billion years?

A)a neutron star

B)a white dwarf

C) a black hole

B)a white dwarf

Which of the following sequences correctly describes the stages of life for a low-mass star?

A) red giant, protostar, planetary nebula, main-sequence, white dwarf

B) protostar, red giant, main-sequence, planetary nebula, white dwarf

C)protostar, main-sequence, red giant, planetary nebula, white dwarf

D)protostar, main-sequence, white dwarf, red giant, planetary nebula

E) white dwarf, main-sequence, planetary nebula, red giant, protostar

C)protostar, main-sequence, red giant, planetary nebula, white dwarf

How does the Sun produce the energy that heats our planet?

A)When you compress the gas in the Sun, it heats up. This heat radiates outward through the star.

B)Hydrogen atoms are combined into helium atoms inside the Sun's core with the release of energy.

C)The core of the Sun has radioactive materials that give off energy as they decay into other elements.

D)The gases inside the Sun are on fire, they are burning like a giant bonfire

B)Hydrogen atoms are combined into helium atoms inside the Sun's core with the release of energy.

Chapter 13 Question 27, page 360: Stars can form most easily in clouds that are

warm and dense.

cold and dense.

hot and low-density.

cold and dense.

Consider the information given below about the lifetime of three main sequence stars A, B and C.

Star A will be a main sequence star for 45,000 million years

Star B will be a main sequence star for 50 million years

Stars C will be a main sequence star for 3 million years

Which of the following is a true statement about these stars?

A)Star A has the greatest mass

B)Stars A, B and C have approximately the same mass

C)There is not enough information to determine the answer

D)Star C has the greatest mass

D)Star C has the greatest mass

What type of star is our Sun?

A high mass star

A low mass star

A low mass star

Chapter 13 Question 30, page 360: Which of these stars does not have fusion occurring in its core?

a blue main-sequence star

a red main-sequence star

a red giant

a red giant

The maximum mass of a low mass star is

8 times the Sun's mass

10 times the Sun's mass

20 times the Sun's mass

3 times the Sun's mass

5 times the Sun's mass

8 times the Sun's mass

What is a protostar?

a star in its final stage of life

a star that has planets

a star that is still in the process of forming

a star that is still in the process of forming

Which of the following parameters is the most crucial in determining the fate of a single star?

its distance from Earth

its mass

its luminosity

its radius

its mass

We know that stars produce new elements in their cores through nuclear fusion.

But which stars would have released their new elements so that new stars, planets, moons, et cetera could form?

solitary white dwarfs and supernova explosions involving single, massive star or a white dwarf in a close binary system

A)a solitary white dwarf

B)a white dwarf in a close binary system that explodes in a supernova explosion

C)a single, massive star that dies in a supernova explosion

D)white dwarfs that are solitary or in close binary systems

E)supernova explosions involving a single, massive star or a white dwarf in a close binary system

F)a single, massive star or a single white dwarf

E)supernova explosions involving a single, massive star or a white dwarf in a close binary system