PHYSICAL PROPERTIES OF BONDS

Question 1

What is the process called when a solid turns to a liquid? (1)

Answer 1

called fusion.

Question 2

what is the process called when a liquid turns to a gas? (1)

Answer 2

called vaporisation.

Question 3

what forces hold crystals together? (2)

Answer 3

the particles have a regular arrangement and are held together by forces of attraction. these could be strong bonds or weak intermolecular forces. The strength of this attraction effect the properties.

Question 4

what are the different types of crystal? (4)

Answer 4

ionic, metallic, molecular and macromolecular crystals.

Question 5

what are ionic crystals? (2)

Answer 5

-they have strong electrostatic forces of attractions between oppositely charged ions.
-have high melting points

Question 6

what are metallic crystals? (2)

Answer 6

-exist as a lattice of positive ions embedded in a delocalised sea of electrons.
-high melting points.

Question 7

what are the properties of molecular crystals? (3)

Answer 7

-crystals are soft and break easily
-low melting temperature and sublimes readily
-does not conduct electricity

Question 7

what are molecular crystals? (2)

Answer 7

consist of molecules held in a regular array by intermolecular forces, covalent bonds within the molecules hold the atoms together but they do not act between the molecules.

Question 8

what are macromolecular crystals? (1)

Answer 8

the covalent bonds extend throughout the compound and have the typical property of a giant structure held together with strong bonds.

Question 9

what are some examples of macromolecular crystals? (3)

Answer 9

-diamond
-graphite
-buckminsterfullerene

Question 10

what are the properties of diamond? (3)

Answer 10

-very hard material
-very high melting temperature
-does not conduct electricity because there are no free charged particles to carry charge

Question 11

what are the properties of graphite? (3)

Answer 11

-a soft material
-very high melting temperature
-it conducts electricity along the planes of the hexagons

Question 12

what is the structure of diamond? (1)

Answer 12

each carbon atom forms 4 single covalent bonds with the other carbon atoms. these four electrons repel each other.

Question 13

what structure is graphite? (2)

Answer 13

each carbon atom forms three single covalent bonds to other carbon atoms, these form a flat trigonal arrangement leaving each carbon with a spare electron in a p-orbital that is not part of these bonds.

Question 14

what type of intermolecular forces occur between graphite? (2)

Answer 14

strong covalent and weak van der waals forces.