CHEMISTRY BRIDGE

• Ionic Bonding is the process of transferring electrons.
• Covalent Bonding is the process of sharing electrons.
• Chemical Bonding refers to the attractive forces that hold atoms together in compounds.
• Metallic Bonds occur between atoms within metallic elements.
• The periodic table of elements is a concise, information-dense catalog of all the different sorts of atoms in the universe
• Dmitri Ivanovich Mendeleev became the crown jewel of Russian science, and a theorist who revolutionized how we see the world
• Groups of elements in the periodic table

  • Alkali metals
  • Alkaline earth metals
  • Transition metals
  • Halogens
  • Metalloids, gases, and nonmetals
  • Lanthanides and actinides
  • Noble gases
• Alkali metals


  • Soft, shiny, extremely reactive
  • Have to be stored in inert gases or oil
  • Want to dump off an electron and form a positive ion
• Alkaline earth metals


  • Reactive metals, but not as reactive as alkali metals
  • Form cations with two positive charges
• Transition metals


  • Metals you think of as metal
  • Fairly unreactive
  • Good conductors of heat and electricity
  • Malleable and can be bent and formed
• Halogens


  • Extremely reactive gases
  • Form negative ions with one negative charge
  • Love to react with alkali and alkaline earth metals
• Lanthanides and actinides


  • Metals that were largely undiscovered in Mendeleev's day
  • Very similar to each other, making them hard to separate
• Noble gases

  • Completely unreactive
• Atomic theory


  A well-tested set of ideas that explains many disparate observations
• Einstein mathematically proved the existence of atoms and molecules in 1905
• Brownian motion


  Random jiggling of pollen grains in water, caused by as-yet-unproven atomic particles smacking into them
• Atom


  The smallest unbreakable bit of a substance
• Subatomic particles

  • Proton (heavy, positively charged)
  • Neutron (about same size as proton, neutral)
  • Electron (very small mass, opposite charge to proton)
• Nucleons


  Protons and neutrons that make up the nucleus
• Atomic number


  The number of protons in an atom, which determines the element
• The atomic number sits on top of the box in the periodic table because it is the element's defining trait
• The strong nuclear force is the strongest of the four fundamental forces of physics, and holds nuclei together
• Neutrons


  Act as a buffer between protons in the nucleus
• Isotopes

  Atoms of the same element with different numbers of neutrons
• Mass number


  Total number of nucleons (protons and neutrons) in the nucleus
• John Newlands published a paper in 1865 on the periodicity of elements, comparing their repetition to a musical scale
• Newlands theorized that lithium was just sodium but an octave higher, and that they were in a sense the same note
• Quanta


  Discrete packets of energy given off by electrons
• Niels Bohr


  Physicist who came up with a model for describing energy levels of a single electron in hydrogen
• Bohr's model failed when applied to more complicated atoms, as electrons don't behave like particles but are better described as waves.
• Wave-particle duality


  The idea that electrons can be described as both particles and waves
• Standing waves


  Waves that are produced around a nucleus at certain energy levels, with anything in between not allowed
• Erwin Schrodinger


  Physicist who developed a mathematical model where the electron was assumed to be a standing wave
• Electron shells

  Discrete energy levels that electrons occupy around a nucleus
• Electron orbitals


  Specific shapes/configurations that electrons can occupy within each shell
• Types of electron orbitals

  • s-orbital
  • p-orbital
  • d-orbital
  • f-orbital
• Octet rule


  The tendency for lighter elements to have 8 electrons in their outer shell
• Electron configuration

  A condensed way of showing where all of an atom's electrons are located
• Electrons don't always fill orbitals in the expected order, as the 4s orbital is filled before the 3d orbital
• Ionization energy


  The energy required to remove an electron from an atom to form a positively charged ion