Chemistry Notes on Atomic Structure, Electron Configuration, Periodic Trends and Bonding

Electron Configuration Table

Electron Configuration

Paramagnetic - elements that have unpaired electrons

Dimagnetic - elements that do not have unpaired electrons

Pauli Exclusion Principle - No 2 electrons can have identical quantum numbers and will be found in opposite spins as marked by a (-1/2 and 1/2)

Degenerate orbitals - orbitals with the same principal energy levels (n) have the same amount of energy because there is no electron-electron repultion, only proton-electron attraction and kinetic energy motion.

Principal Energy Levels(n)

• 1
• 2
• 3
• 4
• 5
• 6
• 7

Sublevels (L)

• s
• sp
• spd
• spdf
• spdf
• spdf
• spdf

Excited Electron States

Wavelength and Photons

When you excite an electron (give it energy) it moves to a higher energy level. When it returns to the ground it gives off wave energy (some type of light). 

• Speed of light: λv=C
• Plank's Constant: ΔE=hv
• v=hertz/frequency (cycles per second)
• Energy=mass x the speed of light (C0
• deBroglie's Equation: λ=h/(m)(v)

Periodic Table Trends

• Ionization energy - decreases down a group, increases across a period
• Electronegativity - decreases down a group, increases across a period
• Atomic Radius - increases down a group, decreases across a period

Bonding (VSEPER)

***The electrons ALWAYS want to be as far apart as possible!***

Number of electron pairs and VSEPER (Valance Shell Electron Pair Repulsion) arrangement.

• 2 pairs = linear
• 3 pairs = Trigonal planar
• 4 pairs = tetrahedral
• 5 pairs = Trigonal bipyramidal
• 6 pairs = Octahedral

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Comments

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