Giant Covalent Bonds

What are allotropes?

• Molecules made entirely of carbon

• Isotopes of carbon

• Compounds formed from two or more elements

• Different structural forms of the same element in the same physical state

How many carbon atoms is each carbon atom in diamond bonded to?

• 2

• 3

• 4

• 6

Imagine you're wearing a diamond ring during a thunderstorm. Why doesn't the diamond in your ring conduct electricity and protect you from a lightning strike?

• It has free electrons

• It is not a covalent structure

• It has no free electrons or ions

• It has a low melting point

What makes graphite different from diamond in terms of its structure?

• Graphite is not a covalent structure

• Graphite atoms are bonded to four other carbon atoms

• Graphite is made of large flat sheets arranged on top of one another

• Graphite has a lower melting point

Why can graphite conduct electricity?

• Because it has no free electrons

• Because it has a high melting point

• Because it has delocalized electrons

• Because it is made of hexagons

What is graphene?

• A type of fullerene

• A single layer of diamond

• A molecule made entirely of hydrogen atoms

• A single layer of graphite

How are the layers in graphite held together?

• By metallic bonds

• Strongly, with covalent bonds between them

• Weakly, with no covalent bonds between them

• By ionic bonds

What property of diamond makes it an excellent thermal conductor?

• Its covalent bonds

• Its ionic bonds

• Its metallic bonds

• Its molecular structure

Why is diamond considered to be the hardest natural substance?

• Because of its high melting point

• Because of its unique crystal structure

• Because it is made entirely of carbon atoms

• Because of its molecular bonds

What feature of graphite allows it to be used as a lubricant?

• The ability to conduct electricity

• The strength of its covalent bonds

• The layers can slide over each other easily

• Its high melting point