Chapter 5 - The Electron (by Nicholas Delor) (What I know (1 oribital = 2e…
Chapter 5 - The Electron (by Nicholas Delor)
Evolution of the Atom 1800-1935
Dalton Model (1803) - John Dalton pictures atoms as tiny, indestructible particles with no internal structure.
Thomson Model (1897) - J. J. Thomson, a British scientist, discovers the electron. The later leads to his "plum-pudding" model. He pictures electrons embedded in a sphere of positive electrical charge.
Rutherford Model (1911) - New Zealand physicist Ernest Rutherford finds that an atom has a small, dense, positively charged nucleus. Electrons move around the nucleus.
Bohr Model (1913) - In Niels Bohr's model, the electron moves in a circular orbit at fixed distances from the nucleus.
Electron Cloud Model (1926) - Erwin Schrodinger develops mathematical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model.
4s(2) 4p(6) 4d(10) 4f(14)
3s(2) 3p(6) 3d(10)
5s(2) 5p(6) 5d(10) 5f(14)
6s(2) 6p(6) 6d(10)
What I know
1 oribital = 2e-
Find outside Nucleus
Opposite charge of a proton (c+)
Electrons are small
Negative charge (1-)
1840e- = 1pt mass
Principles and Rules
Electrons occupy the orbitals of lowest energy first.
Pauli Exclusion Principle
An atomic orbital may describe at most 2 electrons.
Electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin directions large as possible.
Heisenberg's Uncertainty Principle
It is possible to know the velocity and location of an electron... but not both at the same time.
BONUS: Significant Figures Rules
2. Any zeros between two significant digits are
3. A final zero or trailing zeros in the decimal form
1. Non-zero digits are always