Day 2: Periodic Trends and Bonding Flashcards
Metals _____ electrons
lose
Non-Metals_____ electron
gain
Z-S =Zeff
Greater Zeff = smaller the atomic radius.
Electrons are held closer to nucleus
Ionic radius increases
Down and to the left
France has wine & cheese = Fr biggest atomic radius
Isoelectronic series
Most (+) smallest radius
Most (-) largest radius
1st Ionization energy
Energy needed to remove an electron from the first shell
endothermic
oxidation
**Exceptions - B, O, N)
Electron affinity
energy change associated with gaining an electron
Trend: to the right ( more (-))
Ionic bonding
Exothermic Reduction
Electronegativity
Increases up and to the right
Covalent bonding
Exceptions: Be/N
More polar bond
Bigger electronegativity difference
Covalent network solids
Diamond & Quartz
non-metal with non-metal
Sharing e-
Ionic (ionic crystals)
metal with non-metal
crystaline, high melting/boiling point
brittle
Metalic (metalic lattices)
metal with metal Valance e- loosely held Electrical/thermally conductive Ductile- draw them into wires easily & malleable luster/shiny high melting/ boiling point
Molecular
lower m.p. & b.p.
2 non-metals
Lewis dot structures
***Exceptions: CH4, CO2, SF4)
Polar covalent bonds
electrons shared by the atoms spend a greater amount of time, on the average, closer to the more electronegative atom, causing a dipole
Coordinate covalent bonds
A covalent bond is formed by two atoms sharing a pair of electrons. The atoms are held together because the electron pair is attracted by both of the nuclei.
Lewis base & Lewis Acid
NH3 + HCl –> NH4Cl
Exceptions to the octet rule
H -2 Be- 4 B- 6 Al- 6 Can exceed octet- 3rd row or lower odd #
Atoms on the left of the fisher projection
Axial position
Atoms on the right of the fisher projection
Equatorial position
Lone pairs are put here due to large repulsion
Hybirdization
Electrons are promoted (sp, sp2, sp3, sp3d, sp3d2)
Electron domain - 2
non bonding pairs of e- = 0
sp
180 degrees
Electron Geometry -linear
Molecular Geometry- linear
Electron domain - 3
non bonding pairs of e- = 0
sp2
120 degrees
EG- Trigonal planar
MG- Trigonal planar
Electron domain - 3
non bonding pairs of e- = 1
sp2
120 degrees
EG- Trigonal planar
MG- Bent
Electron domain - 4
non bonding pairs of e- = 0
sp3
109.5 dgrees
EG- Tetrahedral
MG-tetrahedral
Electron domain - 4
non bonding pairs of e- = 1
sp3
109.5 dgrees
EG- Tetrahedral
MG- Trigonal pyrimidal
Electron domain - 4
non bonding pairs of e- = 2
sp3
109.5 dgrees
EG- Tetrahedral
MG- Bent
Electron domain - 5
non bonding pairs of e- = 0
sp3d
90/120 degrees
EG- Trigonal bypyrimidal
MG- trigonal bypyrimidal
Electron domain - 5
non bonding pairs of e- = 1
sp3d
90/120 degrees
EG- Trigonal bypyrimidal
MG- see-saw
Electron domain - 5
non bonding pairs of e- = 2
sp3d
90/120 degrees
EG- Trigonal bypyrimidal
MG- T-shaped
Electron domain - 5
non bonding pairs of e- = 3
sp3d
90/120 degrees
EG- Trigonal bypyrimidal
MG- Linear
Electron domain - 6
non bonding pairs of e- = 0
sp3d2
90 degrees
EG- Octahedral
MG-Octahedral
Electron domain - 6
non bonding pairs of e- = 1
sp3d2
90 degrees
EG- Octahedral
MG-square pyrimidal
Electron domain - 6
non bonding pairs of e- = 2
sp3d2
90 degrees
EG- Octahedral
MG-square planar
Single bond
sigma ( σ )- first bond in multiple bond is σ
Multiple bonds
pi bonds ( π ) always p-p
Inter molecular forces from strongest to weakest
Covalent Ionic Hydrogen bonding Dipole-dipole London dispersion forces- Van der Waals
Hydrogen bonding
F, O, N bond with H2O
Bond required in a pure substance
Dipole- Dipole
ion-dipole (equal in strength to H bonding)
Dipole-induced pole
Inter molecular force for polar molecules
molecule is asymmetric, the bond dipole moments won’t “cancel out” and the molecule will have a net dipole moment and the molecule is therefore polar.
London Dispersal focres
Temporary or transient dipole. All molecules have these
More surface area, the greater the london dispersion forces (non-polar molecules)
Higher intermolecular forces lead to
High b.p./ m.p., higher viscosity, high surface tension
Lower vapor pressure
