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10 terms

chemistry- molecular shape and electron geometry

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linear
- Bonds are areas of electron density
- Angle from bonded pair to bonded pair - 180
- Two areas of electron density (can be bonds or lone pairs)
- These areas will distribute as far away from each other as possible because of VESPR (Valence Electron Shell Repulsion Theory)
trigonal planar
- Bond angle of 120 degrees--- between each electron density there are equal repulsive forces
- These include boron, aluminum, or anything with three valence electrons
- It has equalatieral planes and an axial plane of 90 degrees
- three areas of electron density
Tetrahedral
- Most common because many covalent bonds have 5 electrons around the central atom
- It is composed of four equilateral triangles
- There is a 109.5 angle between each
- Appears on the test most
-4 areas of electron density
trigonal bipyramidal
- Three triangles at the top
- Composed of two pyramids top and bottom
- Composed of five bonded pairs- the amount of attraction and repulsion is equal
- five areas of electron density
octahedral
- Six bonded pairs
- 12 electrons around the central atom
- Commonly found in the oxygen family
bent
- a bent version of the electron geometry, occurs when you have two lone pairs
- polarity of molecule and bond is huge (more protons at theend and electrons at the other end)
expanded octet
takes more than 8 electrons. This is common in the nitrogen family because nitrogen has five valence electrons
lone pair
no nucleus, bigger than the bonded pairs because there are electrons in the orbital but no positively charged nucleus of another atom to pull it up
why does a lone pair make the space between the bonded pairs smaller in molecular shape?
o Lone pair distributes more repuslivity to other pairs and pushes them closer together. There is no positive charge in the form of the nucleus of another atom to pull up the lone pair because lone pairs are not bonded to anything and so the lone pair can expand outward as much as it needs to, which pushes the other bonded pairs to the sides.
pyramidal
three areas of electron density.