PhySci

• The Solar System appeared

  9 billion years ago
• The first stars appeared

  50-150 million years ago
• Singularity


  One-dimensional point which contains a huge mass in an infinitely small space, where density and gravity become infinite
• Inflation


  Basic homogeneity in distribution of matter was established as a consequence of the first phase of inflation
• Nucleosynthesis


  Nuclear fusion and formulation of new nuclei
• Recombination


  Formation of the capture of free electrons by the cations in a plasma
• Atomic Number


  Number of protons in an atom
• Dmitri Mendeleev


  Created a classification of elements based on their atomic weight
• Henry Gwyn-Jeffreys Moseley


  English physicist who demonstrated that the atomic number of protons determines the most of the properties of the element
• Researcher at Rutheford's laboratory


  Demonstrated that major properties of an element are determined by the atomic weight
• Transuranium Elements


  Elements with an atomic number greater than 92
• Ernest Rutherford


  Carried out a nuclear transmutation reaction
• James Chadwick


  Discovered the neutron in 1932, previously known as the neutral particle
• Particle Accelerator


  Used to synthesize new elements
• Ernest Lawrence


  Synthesized elements with atomic number 43 using a linear particle accelerator
• Chemical Evolution


  Low mass stars synthesize new He, C, O during the main sequence, RGB, HB, and AGB phases
• Chemical Evolution II


  For massive stars, equilibrium's fusion reactions produce elements all the way up to Fe
• Chemical Evolution III


  Equilibrium fusion reactions of light elements don't proceed past FE because of Fe's location at the peak of the curve of binding energy
• Neutron Capture


  • Slow/S-process - slow rate of capturing neutron; faster rate of radioactive decay, hence increasing the proton by 1
  • Rapid/R-process - faster rate of capturing neutron before it undergoes radioactive decay
• Marie Curie


  Discovered Polonium, the first naturally occurring unstable element that was isolated
• Pauling Electronegativity Values


  • Ionic > 1.7
  • Polar Covalent 0.5 to 1.6
  • Nonpolar Covalent < 0.4
• Polar Covalent Bond


  Formed when electrons are shared unequally by two atoms in a compound
• Nonpolar Covalent Bond


  Formed when atoms are shared equally between two atoms
• Lewis Structure


  Simplified representation of the valence shell electrons in a molecule
• Bond Dissociation Energy


  Energy that is needed to pull the atoms apart
• Solubility


  Ability of a substance to dissolve in a given amount of solvent
• Miscibility


  Ability of two liquids to combine or mix in all proportions; homogeneous mixture
• Intermolecular Forces of Attraction

  • Metallic bond
  • Ionic bond
  • Covalent bond
• Intermolecular Forces


  • Dipole-dipole interaction
  • Hydrogen bonding
  • London dispersion Forces
• Boiling Point


  Temperature at which the vapor pressure and atmospheric pressure are equal; IMFA = BP
• Melting Point


  Temperature at which solid becomes liquid
• Surface Tension


  Energy required increasing the surface area of a liquid by a unit of area
• Viscosity


  Resistance of the liquid to flow
• Vapor Pressure


  Pressure exerted by a substance in its gaseous state
• Volatility


  Measures the rate at which a substance vaporizes
• Van der Waals forces


  Consists of dipole-dipole interaction, dipole-induced dipole interaction, London dispersion Forces