S2.2 extra Flashcards
1
Q
what are allotropes
A
- different forms of the same element
- in the same physical state
2
Q
graphite
A
- molecular compound
- layered structure (layers held by intermolecular forces - london disp forces)
- layers can slide over eachother
- has delocalised electrons (good conductor of electricity)
3
Q
graphene
A
- very thin (one layer)
- very strong
- has delocalised electrons (good electrical and thermal conductor)
4
Q
diamond
A
- giant covalent structure
- very strong covalent bonds between the atoms
- high melting point and boiling point
- very hard (physically) bc of strong covalent bonds
5
Q
fullerene (C60)
A
- molecular compound
- structure has 12 pentagons and 20 hexagons
- has some electrical conductivity but very poor
6
Q
Rf value
A
- Rf = distance travelled by solute/distance travelled by solvent front
7
Q
define hybridisation
A
hybridisation: the mixing of atomic orbitals to produce hybrid orbitals used for bonding
8
Q
intermolecular force between non polar and polar
A
induced dipole
- these IM forces are attraction between positive and negative dipoles
9
Q
why are all resonance structures conductors
A
all have delocalised pi electrons (electrons shared over two nuclei)
10
Q
structure of actual benzene
A
planar regular hexagon
11
Q
sigma bond definition
A
head on overlap of two atomic orbitals (either S or P)
12
Q
pi bonds definition
A
lateral overlap of 2 P orbitals
13
Q
word for same amount of energy
A
degenerate
