Physical Science Lesson 1 Flashcards
most prevailing model of the origin of the universe; described the universe expanded about 13.7 billion years ago
The Big Bang Model
In 1948, ___________, ____________, __________ published a paper entitled “The Origin of Chemical Reactions”.
Ralph Alpher, Dr. Hans A. Bethe, & George Gamow.
a process by which all of the elements in the universe could have come into existence shortly after the big bang
The origin of Chemical Elements
process where two or more nuclei combine to form a new element
fusion reaction
Life Cycle of a Star
1.Nebula
2. Protostar
3. Main Sequence Star
4. Giant
5. White Dwarf
6. Neutron Star
7. Black hole
It refers to the production of nuclei other than H-1 (the normal, light hydrogen) shortly after the Big Bang.
Big Bang Nucleosynthesis (BBN or Primordial Nucleosynthesis)
It is also believed that this process (BBN) is responsible for the formation of:
- Hydrogen (H-1)
- Deuterium (H-2, a hydrogen atom)
- Helium isotopes
(HE-3 and HE-4) - Lithium isotope (Li-7)
- Trace amounts of Beryllium (Be)
A star is formed when a cloud of gas and dust collapse to the point where the material in the center of the clump is so dense and hot that nuclear fusion of hydrogen nuclei and helium nuclei occurs
— The outflow of energy released by these reactions provide the pressure necessary to halt and collapse. The pressure and gravity are in hydrostatic equilibrium.
Stellar Nucleosynthesis
A low-mass star ends up as a
white dwarf
A high-mass star ends up either as a
neutron star or blackhole
Life Cycle of a Star
- Nebula
- Protostar
- Main sequence star
- Giant
- White dwarf
Massive stars become larger than giants as they leave the main sequence… they can be 100 to 1,000 times larger than the sun.
Supergiant
the explosion of a supergiant
Supernova
a small dense ball of neutrons that spin after a supernova explosion
Neutron Star
the remnants of a supernova that are contracted even more than a neutron star …. It is so dense light cannot escape from it.
Black Hole
