Earth and Space Science / Unit 10: Stars, Galaxies and the Universe
10.4 Elements, Black Holes and Neutron Stars
Notes
- The Big Bang made mostly hydrogen and helium. Stars made the heavier elements by fusion; supernovae scatter them. We are made of "star stuff."
- A neutron star is a collapsed core only about 20 km across but with more mass than the Sun, so extremely dense.
- A black hole has gravity so strong that not even light escapes. Its edge is the event horizon. It is detected by its effect on nearby matter.
- Black holes do not suck in everything; far away, they pull like any object of the same mass.
Practice
Where did most elements heavier than helium come from?
Stars build heavier elements.
What defines a black hole?
Escape speed exceeds the speed of light.
The boundary around a black hole beyond which nothing can escape is the:
The event horizon is the point of no return.
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