Scientists
Who discovered that electrons could be described not only as particles but also as waves?
De Broglie
Orbits → old idea. _____ → new idea.
Orbitals
What are the 4 quantum numbers called?
Principal Quantum Number → n
Angular Momentum (secondary) Quantum Number → l
Magnetic Quantum Number → ml
Spin Quantum Number → ms
Define Orbital.
A region of space around the nucleus where an electron is likely to be found.
List the 3 ways electron configuration can be written.
Energy level diagrams, complete electron configuration, condensed electron configuration.
Who conducted the Gold Foil Experiment (old idea)?
Rutherford
True or false; orbital circumference has to fit whole waves (1, 2, 3) and not part of waves (1.5).
True
State the Pauli Exclusion Principle.
Pauli Exclusion Principle: no 2 electron can have the same 4 quantum numbers in an atom - electrons sharing an orbital have opposite spins.
State the Aufbau Principle and Hund’s Rule.
Aufbau Principle: each electron is added into the subshell with the lowest energy orbital available.
Hund’s Rule: each orbital subshell gets a single electron first and then an electron can pair. All electrons are ‘up’ when single.
How many electrons can the s, p, d, f subshells hold?
s → 2
p → 6
d → 10
f → 14
Who is responsible for the old idea of the Nuclear Atomic Theory and in what year was it made?
Dalton in 1809
What (2) parts of the Nuclear Atomic Theory were found to have limitations? State the limitations.
“Atoms are indestructible” → protons, electrons and neutrons are all part of an atom. Atoms are composed of subatomic particles, they’re not indestructible.
“All atoms of one element are identical” → some elements have different isotopes.
What are the possible quantum numbers for the 4th electron in the 5f orbital?
n = 5
l = 3
ml = 0
ms = +1/2
List the differences between orbits and orbitals.
Orbits: 2-dimensional ring, electron is a fixed distance from nucleus, 2, 8, or 18 electrons per orbit.
Orbitals: 3-dimensional space, electrons are a variable distance from the nucleus, 2 electrons per orbital.
When writing the complete electron configuration of an atom, do you start by writing the noble gas that comes before or the alkaline earth metal?
Noble gas
What is Heisenberg’s Uncertainty Principle?
Due to the wave nature of matter, it is impossible to predict both the position AND momentum of an electron with certainty.
State the limitations of the discoveries made through the Gold Foil Experiment.
Didn’t account for the entire weight. Electrons in motion should continually give off radiation (light) and lose energy so atoms would implode. This energy loss should cause the electrons to collapse into the nucleus. However, matter is very stable, this does not happen.
What are the quantum numbers for the 5th electron in a 3d orbital?
n = 3
l = 2
ml = +2
ms = +1/2
Which of the following is not a real orbital in the p subshell; w, x, y, z ?
w
True or false; in an energy level diagram, energy decreases as you move up the diagram (bottom to top).
False
What did Schrodinger discover?
A wave equation that accurately calculated the energy levels of electrons in atoms.
What are the 3 main ideas of The Quantum Mechanical Model Of The Atom?
Electrons can move between different orbitals by absorbing/emitting quanta of energy (OLD IDEA)
Electrons act like particles and waves (NEW IDEA)
The location of an electron is given by a probability distribution (NEW IDEA)
What are the quantum numbers for the 2nd and 9th electrons in a 4f orbital?
2nd: n = 4, l = 3, ml = -2, ms = +1/2
9th: n = 4, l = 3, ml = -2, ms = -1/2
What 3D shape is formed with; 1 orbital, 3 orbitals and 5 orbitals?
1 orbital = spherical shape
3 orbitals = dumbbell shape
5 orbitals = clover shape
What are the exceptions to “normal” electron configurations and why?
Groups 6 and 11 are the exceptions. This is because the energy of repulsion is greater than the energy difference between the energy levels.