Unit 1-MS1 Flashcards
What did Thomson contribute to atomic theory?
- Used cathode ray tubes and discovered a negatively charged particle in every atom
- Discovered electron
- Plum pudding model
What did Millikan do?
Found weight of electron
What did Dalton’s atomic theory state?
- All matter is composed of atoms
- Atoms of same element have same qualities
- Atoms can’t be created, divided or destroyed
- Combine in ratios to create compounds
What did the quantum mechanical model suggest?
Louis de Broglie suggested that particles could also behave as waves
- Heisenberg stayed the more certain you are of an electrons speed, the less certain you are of it’s location and vice versa (Use electron clouds)
- Schrodinger created an equation with wave functions as the answer which is the basis for atomic theory
What is the angular quantum number?
- l
- Type of orbital (1=s orbital, 2=s and p orbitals)
- Known elements range from s orbitals to f orbitals
What is the magnetic spin quantum number?
- m(s)
- Describes spin of electrons
- must be -1/2 or 1/2
- 2 electrons in the same orbital have different spin quantum numbers
What are the trends for electronegativity, electron affinity, and ionization energy?
- Moving left to right: Decrease
- Moving tip to bottom: Increase
What was Rutherford’s experiment and how did it contribute to atomic theory?
- Blasted gold foil with alpha particles
- Some particles deflected greatly while others passed through
- Confirmed atoms were not dense
- Discovered positively charged particle (Protons)
- Planetary Model
- Nucleus held protons through nuclear forces
What is the Pauli exclusions principle? Hund’s rule? Aufbau principle?
- Pauli exclusion principle: no 2 electrons in the same atom can have the same 4 quantum numbers
- Hund’s rule: for each energy level, every orbital must be filled with one electron before any orbital has 2
- Aufbau principle: Electrons occupy the lowest possible energy level
What is the bond angle of a tetrahedral substance?
109.5
What was Bohr’s model? What did it try to explain? What were it’s shortcomings?
- Stereotypical atom diagram, with electrons rotating around nucleus in specific allowed orbits
- When H2 is energized, it’s electrons jump to a higher energy level, but when they fall they give off energy equal to energy gained (Neon lights)
- Tried to explain H2’s line emission spectrum
- Failed to account for multi electron atoms and the chemical nature of atoms
What’s the difference between a hadron and a meson?
- Hadrons consist of 3 quarks (usually 2 up and 1 down)
- Mesons consist of 1 quark and 1 antiquark
What does light do to a surface if it has a high enough frequency?
Liberates an electron from the surface
What is the principle quantum number and how is it represented?
- n
- Energy level of electron
- n^2=number of electrons in energy level
What is the bond angle of a substance with an electron group geometry that is trigonal bypyrimidal and a molecular geometry of See-saw?
<120+<90
