Extra Info

Question 1

Diamond

Answer 1

• 4 carbon atoms
• hard and rigid structure
• high melting point and poor electrical conductivity
• tetrahedral array by covalent bonds

Question 2

Graphite

Answer 2

• 3 carbon atoms
• layer structure
• covalently bonded in a trigonal planar array
• good lubricant bc of London forces between layers

Question 3

C60

Answer 3

• MOLECULAR structure
• individual c atoms with covalent bonds
• hexagonal structure

Question 4

Trigonal Planor

Answer 4

120

Question 5

Trigonal Pyramidal

Answer 5

107

Question 6

Trigonal Bipyramidal

Answer 6

90 and 120

Question 7

Octahedron

Answer 7

90 and 180

Question 8

Bent

Answer 8

104.5

Question 9

Tetrahedral

Answer 9

109.5

Question 10

Melting

Answer 10

Ionic: high
Metallic: in the middle
Covalent: low

Question 11

Solubility

Answer 11

Ionic: dissolves in water and polar solutions
Metallic: generally don’t dissolve
Covalent: dissolve in non polar solutions

Question 12

Conductivity

Answer 12

Ionic: Water solutions (electrolytes) (not solid state)
Metallic: Conduct well
Covalent: poorly or not at all

Question 13

Other

Answer 13

Ionic: Strong crystal lattice
Metallic: luster and malleability
Covalent: weak crystal structure

Question 14

Formal Charge

Answer 14

shows the favored structure

Question 15

Sigma Bond

Answer 15

when covalent bond formed and two orbitals overlap head on

Question 16

Pi Bond

Answer 16

formed when two parallel p orbitals overlap side on

Question 17

Covalent Network Solids

Answer 17

have repeating network of covalent bonds that extends throughout the solid forming equivalent of one large molecule

• hard
• rigid
• high melting points

Question 18

Allotropes

Answer 18

very different chemical structures of the same element

- oxygen, sulfur, phosphorous and carbon