The Life Cycle and Classification of Stars

Stars, born in nebulae, begin as protostars and undergo thermonuclear fusion, emitting heat and light. They are classified by surface temperature and luminosity. Stars eventually exhaust their hydrogen fuel, with less massive stars becoming white dwarves and more massive ones ending in supernovae or black holes. Stardust from these stars contributes to the formation of life in the universe.

Where do stars originate from?

• Black holes

• Nebulae

• Galaxies

• Asteroids

What is the initial stage of a star's life called?

• White dwarf

• Neutron star

• Protostar

• Supernova

What process in stars generates heat and energy?

• Gravitational collapse

• Thermonuclear fusion

• Nuclear fission

• Chemical reaction

How are stars classified based on their surface temperature?

• By spectral classes

• By their distance from Earth

• By their age

• By their size

Which spectral class represents the hottest stars?

• O

• M

• K

• G

What is the term for the classification of stars based on the light they emit?

• Mass classes

• Luminosity classes

• Spectral classes

• Temperature classes

What remains after a less massive star like our sun dies?

• Red giant

• White dwarf

• Neutron star

• Black hole

What is left behind after a massive star explodes in a supernova?

• Protostar

• Red giant

• Neutron star

• White dwarf

What do the most massive stars become after collapsing?

• Red giants

• Black holes

• Neutron stars

• White dwarfs

What do the remnants of stars contribute to the universe?

• Dark matter

• Heavier elements

• Cosmic rays

• Light energy