Chapter 2

Historical Experiments leading to the Atomic Theory (2.1-2.2)

• Heisenberg Uncertainty Principle
  • Tells us we can't know both the location and velocity of an electron at the same time

Atomic Structure and Composition (2.3)

• Particle Mass
  • measured in kg and atomic mass units (amu)
    • 1/12 mass of atomic Carbon unit (carbon atom)
• Charge
  • Measured in Coloumbs and electronic charge
• Atomic Volume
  • mostly comprised of electron cloud
    • comprised of Electrons
• Atomic Mass
  • mostly comprised of nucleus
    • comprised of Protons and Neutrons
• https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwicjIaYwYTfAhVlmeAKHZ4nCH8QjRx6BAgBEAU&url=http%3A%2F%2Fguillerexploren.blogspot.com%2F2013%2F02%2Fmodelos-atomicos_27.html&psig=AOvVaw1fHv3pisRnJU0qOrbN14G9&ust=1543955650034867

Chemical Symbols and Sub-atomic Particles (2.3)

• The chemical symbol, as pictured in the image below shows the mass number and atomic number as well as the charge and atomic symbol
  • https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjitabEwoTfAhXIT98KHSBdBUgQjRx6BAgBEAU&url=http%3A%2F%2Fdata.allenai.org%2Ftqa%2Finside_the_atom_L_0772%2F&psig=AOvVaw0qCay2NvRbd1GC9TLuqGAx&ust=1543956021104034
  • atomic number is the number of protons
• ions (charged atoms) do not have equal numbers of protons and electrons
  • they have the same amount of protons as the base atom but a different amount of neutrons and electrons
  • cations - positively charged ions
  • anions - negatively charged ions

Isotopes (2.3)

• Isotope abundance and average mass
  • average mass is equal to the sum of the quantity of the fractional abundance multiplied by the isotopic mass
    • represented as mu mass
  • to find the abundance, use the average mass formula and replace fractional abundance with x and 1-x

Empirical/Molecular Formulas and Molecular Weight (2.4)

• molecules - combinations of different atoms bonded together
• each non-hydrogen seeks to have 8 valence electrons by sharing two electrons with another atom in a bond
  • double bonds share 4 electrons
  • triple bonds share 6 electrons
• Mass v. moles
  • moles compare values of mass and/or volume for different molecules
    • Avogadro's number - 6.02x10^23 "things"/mole

Review of grams-to-moles-to-(molecules or atoms) problems