1.5: Atomic Structure and Electron Configuration Flashcards
Bohr’s Model of the Atom
-most prevalent in media
-electrons only exist in certain discrete energy levels, which are described by quantum numbers
-energy is involved in the transition of an electron from one level to another
Limitations to the Bohr Model
-only works for hydrogen
-classical physics says the electron should fall into the nucleus
-circular motion is not wave-like in nature
Core Electrons
the inner electrons
Valence Electrons
the outermost electrons
Electron Configuration
the way electrons are distributed in an atom
Orbital Diagrams
-each box / line in the diagram represents one orbital
-half arrows represent the electrons
-direction of the arrow represents the relative spin of the electron
Energy Levels
-different distances from the nucleus
-different shapes possible
-can overlap in energy (4s is lower in energy than 3d)
Aufbau Principle
-we “build” electron configurations as we go from atom to atom
-orbitals are filled in order of increasing energy
Hund’s Rule
-every orbital in a sublevel is singly occupied before any orbital is doubly occupied
-all of electrons in singly occupied orbitals have the same spin (to maximize total spin)
Pauli Exclusion Principle
-no two electrons in the same atom can have the same set of four quantum numbers
-no two electrons in the same atom can have the exact same energy
-electrons in the same orbital have opposite spins
Main Group Elements
elements in the s and p blocks of the periodic table
Noble Gas Configuration
electron configuration of an element is shortened using the electron configuration of a noble gas, denoted by brackets around the noble gas symbol
Coulomb’s Law
-the strength of the interaction between tow electrical charges depends on the magnitudes of the charges and on the distance between them
- F= k(sub e) x (q(sub 1) x q(sub 2) /r^2)
-q (sub 1) = quantity of charge on object 1
-q (sub 2) = quantity of charge on object 2
-d (or r) = distance of separation between the two objects
(in meters)
Effective Nuclear Charge
-electrons are attracted to the nucleus but also repelled by other electrons
-forces an electron face based on the factors listed above
-Z (sub eff) = Z - S
-Z = atomic number
-S = number of inner/shielding electrons
Shielding Effect
screening effect by inner (core) electrons
-reduces electrostatic attraction between outer electrons and the protons in the nucleus
-effect: protons in the nucleus cannot hold on to the outer electrons as tightly as core electrons
