M2 part 2 Flashcards
a giant balls mostly made of hydrogen and helium
stars
stars are mostly made of
hydrogen and helium
act as sites for nuclear reactions in the universe
stars
fuse light element to form heavier elements
stars
stars functions
- act as sites for nuclear reactions in the universe
- fuse light elements to form heavier elements
why are the stars so bright
reaction involve light emission
the cloud of hydrogen and helium gases
condensed to form stars
stellar nuclesynthesis
how do stars form
cloud of hydrogen and helium gases condensed
stars made of hydrogen became
hotter and denser
during the process of stellar evolution, nuclear reactions continued producing
elements heavier than LITHIUM
HOW DOES HEAVY ELEMENTS FORMED
combination of light elements
Stars much larger than our Sun can fuse
heavier elements from lighter elements
These giant stars have an
“onion layer” structure
As you proceed deeper into the star, temperatures and pressures
increases
what does fused together when you proceed deeper into the star
heavier nuclei
The heaviest element that can be made in a star is
iron (Fe)
In the adjacent diagrams, the term “burning” really means
nuclear fusion
initially fueled young stars and through nuclear reactions, new elements are formed in certain regions or layers of a star
called the fusion shells.
hydrogen
new elements are
formed in certain regions or layers of a star
called the
fusion shells
When most of the hydrogen in the core is
fused into helium, fusion stops and the
pressure in the core
decreases
how does helium-hydrogen burning occurs
when gravity squeezes the star
Gravity squeezes the star to a point that helium-hydrogen burning occurs. Thus, converting
helium to carbon
When the majority of the helium in the core has been converted to carbon…..
the rate of alpha fusion processes decreases
when does the rate of alpha fusion processes
decreases
majority of the helium in the core has been
converted to carbon
formed from carbon fusion
neon
formed from neon fusion
oxygen
formed from oxygen fusion
silicon
formed from silicon fusion
iron
layers of multiple-shell red giant
- hydrogen and helium outer envelope
- helium rich, hydrogen burning shell
- carbon rich, helium burning shell
- oxygen rich, carbon burning shell
- silicon rich, oxygen burning shell
- iron rich, silicon burning inner core
