Chemistry Test Notes

Chemistry Test Notes

1. Dalton Model Change

   • John Dalton, JJ Thompson, Ernest Rutherford, Niels Bohr, James Chadwick
   • Model changed from 1803 through too 1932

2. Structure of an Atom

   • Protons and Neutrons are in the Nucleus
   • Protons are positively charged
   • Electrons are negatively charged
   • Protons are Atomic Number
   • Protons plus Neutrons are Atomic Mass
   • Electrons are Atomic Number or Protons

3. Isotopes

   • Amount of Protons and Electrons never change
   • Neutrons go up by one
   • Mass is doubled proton and then up by one
   • Copies of an element with a different amount of neutrons and mass

4. Relative Formula Mass

   • 1. Breakup different elements in the compound
   • 2. Times them by how much of it there is
   • 3. Add it all up

5. Relative Atomic Mass

   • 1. Mass of Isotope times by percentage of isotope
   • 2. Add both together
   • 3. Divide by 100 to make it a percentage

6. Drawing Atoms as Shells

   • The crosses are made up from amount of protons
   • The first shell can only hold 2
   • The second shell can only hold 8
   • The number of crosses with commas for which shell they are in is called electron configuration