Physical Science

• Big Bang Theory

  • No explosion happened, only a continuous expansion or inflation
  • An intensely hot and infinitely dense object called singularity suddenly inflated and that started the beginning of the universe
  • Space, time, energy, and matter are created after the Big Bang
  • History began after the Big Bang
• Evidence for Big Bang Theory

  • Edwin Hubble's Red Shifting
  • Accidental discovery of Cosmic Microwave Background Radiation
  • Abundance of Hydrogen in the Universe
• Nucleosynthesis


  • The creation of new atomic nuclei, the centers of atoms that are made up of protons and neutrons
  • First occurred within a few minutes of the Big Bang
  • Responsible for the formation of elements

  
• Nucleosynthesis

  1. Fusion - the joining of two nuclei to form a heavier nuclei

  2. Fission - the splitting of a heavy nucleus into two lighter ones

  
• Nuclear Fusion in real life


  • Exists naturally in stars including the Sun, where hydrogen nuclei fuse and create helium while releasing the energy that lights and heats the Earth

  
• Nuclear Fission in real life


  • All nuclear power plants use nuclear fission, and most nuclear power plants use uranium atoms. During nuclear fission, a neutron collides with a uranium atom and splits it, releasing a large amount of energy in the form of heat and radiation

  
• Protium


  The hydrogen's most common isotope. It accounts for more than 99.98 percent of all universe hydrogen. Because its nucleus has only one proton, it is called protium.

  
• Deuterium


  An isotope of hydrogen. In the simple hydrogen molecule, there is one proton, one electron, and no neutrons, protons, electrons, and neutrons being the elementary particles that make up the atom. Deuterium, on the other hand, is composed of one proton, one electron, and one neutron.

  
• Tritium


  A radioactive isotope of hydrogen. It has the same number of protons and electrons as hydrogen but has 2 neutrons, whereas regular hydrogen does not have any. This makes tritium unstable and radioactive.

  
• Big Bang Nucleosynthesis

  1. Protons and neutrons are fused together to form deuterium

  2. Deuterium will collided with other neutrons producing Tritium

  3. Tritium will collided with other protons (protium) producing Helium

  4. Helium will fuse with tritium to formed lithium-7

  
• Other Pathways

  1. 2 deuterium collided and will formed helium-3, add neutron

  2. Two helium nuclei ("alpha particles") fuse to form unstable beryllium. If another helium nucleus can fuse with the beryllium nucleus before it decays, stable carbon is formed along with a gamma ray

  
• Unstable elements


  When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced or unstable. Whether radioactive elements can become stable and if so, how. The unstable nucleus of radioactive atoms emit radiation.

  
• The lightest elements such as H, He, Li, and some trace of Be and B were the only elements formed in the Big Bang Nucleosynthesis.

  
• Every atom in your body was once inside a star that exploded. The atoms in your left hand probably came from a different star than in your right hand, because 200 million stars have exploded to make up the atoms in your body.

  
• Alpha Process


  • Also known as alpha capture or the alpha ladder
  • It is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements
  • One type of process is called Triple-alpha process which consumes only helium and produces carbon

  
• Alpha particles


  • An alpha particle is identical to the nucleus of a normal (atomic mass four) helium atom
  • An alpha particle consists of two protons and two neutrons, so it is actually a helium nucleus.

  
• Elements starting from He up to Fe were the only elements that can be formed within stars through Stellar Nucleosynthesis.

  
• 1. R-process

  • Also called the rapid neutron capture process of stellar nucleosynthesis
  • Is called for to explain the production of the stable neutron-rich nuclides heavier than iron that are observed in stars of various metallicities.

  
• 1. S-process

  • Also called the slow neutron capture process
  • Is a series of reactions in nuclear astrophysics that occur in stars particularly asymptotic giant branch stars
  • It requires pre-existing heavy isotopes as seed nuclei to be converted into other heavy nuclei by a slow sequence

  
• Elements Heavier than Iron (Fe) starting to Cobalt (Co) up to Uranium (U) were the elements that can be formed through Supernova Nucleosynthesis excluding Tc and Pm.

  
• Atom


  • Fundamental unit of mater. It forms various elements, ions, compounds and biomolecules
  • Roughly equal of the sum of the individual particle masses of an atom
  • Have subatomic particles
• Protons


  The proton is a subatomic particle with a positive electrical charge. They are found in every atomic nucleus of every element. In almost every element, protons are accompanied by neutrons. Ernest Rutherford discovered protons in 1900s

  
• Neutrons


  Along with protons, are subatomic particles found inside the nucleus of every atom. Neutrons have a neutral electric charge (neither negative nor positive) and have slightly more mass than positively charged protons. James Chadwick discovered neutrons in 1930s.

  
• Electrons


  A small particle with a negative charge that is found in all atoms. J.J Thompson discovered electrons in 1897

  
• Dalton's Atomic Theory


  • All matter is made of atoms
  • All atoms of a given element are identical in mass and properties
  • The atoms of a given element are different from those of any other element
  • Compounds are combinations of two or more different types of atoms
  • A chemical reaction is a rearrangement of atoms

  
• Schrodinger's Atomic Model


  • Instead of being organized in 2-D orbits, electrons are actually found in 3-D orbitals
  • Each orbital defines an area where the probability of finding an electron is high. These orbitals are known as electron "clouds."

  
• Energy Levels in Elements

  • There are 7 energy levels in the periodic table
  • The four energy levels for electrons are s, p, d, and f
  • s level holds 2 electrons; p level holds 8 electrons; d level holds 10 electrons; f level holds 14 electrons
  • Each subshell holds different numbers of electrons and has different energies. Subshells have a ranking order of increasing energy, which is 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, and 7p, with energy increasing from left to right
• Electron Configuration


  • It is the arrangement of electrons in orbitals around an atomic nucleus. The electronic configuration of an atom in the quantum mechanical model is stated by listing the occupied orbitals, in order of filling, with the number of electrons in each orbital indicated by superscript
  • Third-row and heavier elements often satisfy the octet rule but can exceed the octet rule by using their empty valence d orbitals

  
• Electronegativity


  A chemical property that describes the tendency of an atom or a functional group to attract electrons toward itself
• Chemical Bonding


  Any interactions that account for the association of atoms into molecules, ions, crystals and other species
• Periodic Table


  Organized arrangement of all the chemical elements in order of increasing atomic number
• Atom


  Smallest unit of matter
• Order of increasing energy of electron orbitals

  • 1s
  • 2s
  • 2p
  • 3s
  • 3p
  • 4s
  • 3d
  • 4p
  • 5s
  • 4d
  • 5p
  • 6s
  • 4f
  • 5d
  • 6p
  • 7s
  • 5f
  • 6d
  • 7p
• Electron Configuration


  The arrangement of electrons in orbitals around an atomic nucleus

  
• Third-row and heavier elements often satisfy the octet rule but can exceed the octet rule by using their empty valence d orbitals
• Atom


  Smallest unit of matter that is composed of three sub-atomic particles: proton, neutron and the electron
• Octet rule


  Refers to the tendency of atoms to have 8 valence of electrons
• Exceptions to the Octet rule

  • C, N, O and F should always be assumed to obey the octet rule
  • B and Be often have fewer than 8 electrons around them in their compounds
  • Second-row elements never exceed to the octet rule
  • Third-row and heavier elements often satisfy the octet rule but can exceed the octet rule by using their empty valence d orbitals
• Valence Electrons


  Electrons that reside in the outermost shell surrounding an atomic nucleus

  
• Chemical Bond


  Holds atoms together to form a molecule