physci long test review

• protons are positive charges of an atom
• neutrons are neutral charges of an atom
• electrons are negative charge of an atom
• nuclear fusion is the process where heavy elements are formed
• nucleosynthesis is the process where nucleons combine to form new elements
• the atomic number of an element is the number of protons in it
• an isotope is an element that has the same atomic number, but different atomic mass
• the nebula is a giant cloud of gas and dust that is the birthplace of new stars
• the nebula spins like a disc
• a protostar is an infant star
• to become a main sequence star, the internal force and gravity of a protostar must be equal
• to become a main sequence star, the temperature of a protostar must first reach 10,000 Kelvins
• main sequence star has constant nuclear fusion of helium and hydrogen in its core
• 90% of a star's life cycle happens in main sequence star
• when an average star runs out of hydrogen fuel, it becomes a red giant
• when a massive star runs out of hydrogen fuel, it becomes a red super giant
• when a red giant runs out of hydrogen around its core, it becomes a white dwarf
• heavier elements like iron are formed in a black dwarf
• a red giant or red super giant's core has carbon and oxygen
• the explosion or death of a star is called a supernova
• neutron stars are the brightest and smallest star in the universe.
• a black hole's direction is always towards the center
• as a black hole gets bigger, it gets less dense
• duplet rule states that if the proton and electron in an atom is equal, the atom is stable
• a lone pair only has one electron
• bonding pair or covalent pair has two or more electrons to bond with
• a proton is denser than electron
• the valence electron is located in the innermost energy level of an atom
• helium has a complete set of two valence electrons or the duplet condition
• neon and argon has 8 valence electrons or the octet condition
• the duplet rule states that some elements can be stable with two electrons in their shell
• if the elements are non-metal, they will share the electron, therefore it is covalent bonding
• if the elements are metal, they will transfer the electron, therefore it is ionic bonding
• the big bang started from a primorial atom or a singularity
• the doppler effect was by hubble
• red shift - moving away
• blue shift - moving towards
• andromeda is the closest galaxy to our solar system
• baryonic matter (4%) are the things that we see
• dark energy (71%) counteracts the power of gravity