Life Cycle of Stars and H-R Diagram Review

A set of 50 question-and-answer flashcards covering stellar evolution, nucleosynthesis, and the Hertzsprung-Russell diagram based on the Life Cycle of Stars worksheet.

What is the starting stage of a star's life cycle?

Stellar nebula

What is a stellar nebula mostly made of?

Hydrogen gas

What stage forms when gravity collapses hydrogen into a ball, creating heat?

Protostar

What process creates heat as a protostar forms?

Gravity pulls hydrogen into a dense ball

What mass range is given for a low-mass main-sequence star?

$8$ solar masses or less

What is the mass range of a high-mass main-sequence star compared with the Sun?

$8$ or more solar masses

Which color does the star life-cycle diagram associate with hot temperature?

Blue

In the star life-cycle diagram, which color is associated with cold temperature?

Red

In the star life-cycle diagram, which axis represents a star's brightness?

Luminosity

In the life cycle of a low-mass star, which stage follows the main-sequence stage?

Red giant

What stage follows a high-mass main-sequence star in its life cycle?

Supergiant

What element is produced when hydrogen fusion occurs in a star's core?

Helium

What element does helium fusion produce in a red giant's core?

Carbon

After fusion in the core uses up helium in a red-giant star, what happens next?

The core collapses and ejects gases, forming a planetary nebula

What is the low-mass stellar remnant left after a planetary nebula forms?

A white dwarf

A white dwarf can be described as a hot ball of:

Carbon

What happens after a white dwarf forms in the low-mass star pathway?

It remains a hot carbon ball for trillions of years.

What happens when helium in a high-mass star's core is used up?

The core collapses, and the star heats up, expanding into a supergiant.

Which element is produced when hydrogen fusion occurs in a star's core?

Helium

What happens when iron is used up in the core of a massive star?

Fusion stops, and the star collapses and then explodes in a supernova.

What event occurs when fusion stops in a massive star's core and the star collapses?

A supernova

According to the diagram, what does a supernova create?

All elements on the periodic table

What type of gas cloud is produced after a supernova?

Enriched nebula

What are the possible compact remnants of a high-mass star?

Neutron stars or black holes

What does the core become in the pathway that ends as a neutron star or black hole?

A ball of neutrons or a point of infinite mass

How are blue and red stars positioned along the temperature scale in the diagram?

Blue stars are on the hot side; red stars are on the cold side.

Where are bright and dim stars positioned on the luminosity axis in the diagram?

Bright stars are higher; dim stars are lower.

Which pathway applies to a star with eight or fewer solar masses?

Red giant $\rightarrow$ planetary nebula $\rightarrow$ white dwarf

According to the star life-cycle diagram, which pathway applies to a star with more than eight times the Sun's mass?

Supergiant $\rightarrow$ supernova $\rightarrow$ neutron star or black hole

In the high-mass pathway, what happens when fusion fuel in a star's core is used up?

The core collapses, and the star heats up.

Which sequence gives the first three stages in a star's life cycle?

Stellar nebula $\rightarrow$ Protostar $\rightarrow$ Main-sequence star

For a low-mass star, which sequence shows its path from the red giant stage to its final stellar stage?

Red giants $\rightarrow$ planetary nebula $\rightarrow$ white dwarfs

In the high-mass star pathway, what event follows when the core uses up iron, fusion stops, and the star collapses?

A supernova

What happens to a star’s core after a supernova?

The core collapses into neutrons or a point of infinite mass, leaving a neutron star or black hole.

A star is six times the size of the Sun.Which pathway will it follow?

Stellar nebula $\rightarrow$ protostar $\rightarrow$ low-mass main sequence $\rightarrow$ red giant $\rightarrow$ planetary nebula $\rightarrow$ white dwarf

The life cycle of a star that is ten times the size of the Sun.

High-mass main sequence $\rightarrow$ supergiant $\rightarrow$ supernova $\rightarrow$ neutron star or black hole

Which event leads to the formation of a planetary nebula?

The core uses up helium, collapses, and ejects gases.

Which pathway shown leads to an enriched nebula?

High-mass main-sequence star $\rightarrow$ supergiant $\rightarrow$ supernova $\rightarrow$ enriched nebula

During which stage does a star's core fuse helium into carbon?

The red giant stage

At which stage does a star's core fuse helium into iron?

Supergiant

When a massive star uses up the iron in its core, what happens next?

The core collapses and then a supernova.

Which statement correctly names the final outcomes shown for low-mass and high-mass stars?

Low-mass stars end as white dwarfs; high-mass stars end as neutron stars or black holes.

Where are white dwarfs located on a H-R diagram

Bottom left with Low luminosity and higher temperatures.

Where are Main Sequence stars on the H-R diagram?

From the top left with high luminosity and temperature down to bottom right with low luminosity and temperatures.

Where are supergiants located on the H-R diagram

At the top with bright luminosity and medium to low temperatures.

Where are red giant stars located?

Medium luminosity and low temperatures on the right side of the H-R diagram.

Which sequence correctly shows how a stellar nebula can become a neutron star or black hole?

Stellar nebula $\rightarrow$ protostar $\rightarrow$ high-mass main-sequence star $\rightarrow$ supergiant $\rightarrow$ fusion stops after iron forms $\rightarrow$ supernova $\rightarrow$ collapsing core forms a neutron star or black hole

A star has very high luminosity and is yellow in color. What kind of star is it?

Supergiant

A star is very dim and white in color. What kind of star is it?

White dwarf

A star has medium luminosity and is red in color. What kind of star is it?

Red Giant