Properties of matter

• atomic mass = # protons + # neutrons
• core charge


  the amount of protons deticated to the valence shell
• Why do atoms get bigger as they go down each column

  the atoms need more electrons which will require more shells and therefore push the valance shell out
• why do atoms get smaller as you go to the right in each row

  the core charge is bigger which attracts the valance electrons more which shrinks the valance shell making the atom smaller
• The 18th comulmn are the noble gases and are the least reactive
• the 1st column is the most reactive and are the alkali metals
• what does C.R.V stand for when refering to atoms

  Core charge, Radius(atomic), Valance shell
• Hydro gas is composed of

  Two hydrogen atoms bonded together
• Signs of chemical change

  Color, smell, temperature, exothermic, endothermic, sound, precipitate
• Cation formula: neutral atom + first ionization energy makes a positively charged atom + an electron
• First Electron affinity is how much energy is released when adding one more electron to a neutral atom
• First Ionization energy is how much energy it takes to remove one molecule from its elemental state
• Anion formula: neutral atom+electron makes negative 1 charged atom+electron affinity(energy)
• Electronegativity is the ability possessed by an atom to attract electrons to itself
• The farther appart two elements are in electronegativaty, the more ionic their bond will be. The closer together the elements are will mean the bond is more covalent
• Covalent bonds can either be polar or non-polar. Polar being their difference in EN is closer to 1.7 and non-polar being closer to 0.
• Chemical change


  A change in the chemical properties of a substance
• Atomic radius


  Distance between the center of the nucleus and the outermost shell of an atom
• Ions

  • Positive ions
  • Negative ions
• Types of elements

  • Metals
  • Metalloids
  • Non-metals
• Similar elements live close together
• CRV Diagrams


  Plot of the core charge vs. the distance from the nucleus
• Ionization Energy


  amount of energy required to remove an electron from an atom
• Birthplace of the elements

  • Earth
  • Space
  • Laboratory
• Bohr-Rutherford Diagrams


  Orbits/core/valence/electron/nucleus
• Ionic radius


  Distance between the center of the nucleus and the outermost ion of an atom
• Physical change


  A change in the physical properties of a substance
• Electronegativity


  Ability of an atom to attract electrons
• Dimitri Mendeleev


  organized the periodic table the way it is
• Nucleosynthesis


  The creation of elements in the core of a star. Either through nuclear fusion or fission.
• Cation


  Positvely charged ion
• Anion


  Negatively charged ion
• Red waves


  Longer wave length
• Violet waves


  Shorter wave length
• Hydrogen emits four colours of light, each element emits a unique spectrum
• Neutron


  A neutral particle in the nucleus of an atom, having no charge (neither positive nor negative)
• Rutherford predicted the presence of a third subatomic particle with the same mass as the proton but with no charge
• First Ionization energy


  Amount of energy required to remove an electron from an atom
• Isotopes


  A variety of neutrons
• Hydrogen 


  Alpha particle created with nuclear reactions