Life Cycle of a Star

What is the temperature at which the surrounding material's pressure in a forming star reaches to initiate nuclear fusion?

• 10 million degrees

• 15 million degrees

• 20 million degrees

• 25 million degrees

Tags

NGSS.HS-ESS1-1

What primarily causes a star to begin shining?

• The accumulation of dust

• The outward pressure balancing the inward pull of gravity

• The color change of the star

• The decrease in temperature

Tags

NGSS.HS-ESS1-1

What determines the size and color of a new star?

• The star's distance from Earth

• The amount of hydrogen it contains

• The amount of gas and dust collected during its formation

• The star's proximity to other stars

What keeps a star "intact" against the force of gravity?

• The star's rotation around its axis

• The electromagnetic radiation it emits

• The nuclear reactions in the star's core

• The gravitational pull from nearby stars

Tags

NGSS.HS-ESS1-1

What ultimately leads to a star's demise?

• Loss of mass

• Increase in size

• Running out of hydrogen

• Cooling down of the core

What happens to a medium size star like our Sun after it reaches the red giant phase and runs out of helium to fuse in its core?

• It explodes into a supernova.

• It becomes a black hole.

• It turns into a black dwarf.

• It transforms into a white dwarf and eventually may become a black dwarf.

Tags

NGSS.HS-ESS1-1

What is the fate of massive stars (5 or more times the mass of our Sun) after they become red supergiants?

• They stabilize and remain red supergiants indefinitely.

• They shrink into white dwarfs.

• They explode as supernovae and then might form black holes or neutron stars.

• They turn directly into black dwarfs.

During the formation of a star, what temporarily counteracts the force of gravity causing the star to expand?

• The decrease in temperature and pressure.

• The fusion of helium into heavier elements.

• The generation of heat from the contraction of material.

• The loss of hydrogen in the outer layers.

What is the primary reason that stars like our Sun eventually turn into white dwarfs?

• Loss of all nuclear fuel and the repulsion of electrons in the core.

• Increase in size and escape of outer layers into space.

• Continuous fusion of helium into heavier elements.

• Expansion and cooling of the outer layers.

Tags

NGSS.HS-ESS1-1

What happens to a star's core when it runs out of iron to fuse, leading to a supernova?

• The core becomes stable and stops changing.

• The core temperature decreases gradually.

• The core temperature rises to over 100 billion degrees as iron atoms are crushed together.

• The core disperses into space without any significant reactions.

Tags

NGSS.HS-PS1-8